Lecture07_Single_Stub_Shunt_Tuning

1M × 4 BANKS × 32BITS SDRAM Table of Contents-1.GENERAL DESCRIPTION (3)2.FEATURES (3)3.AVAILABLE PART NUMBER (3)4.BALL CONFIGURATION (4)5.PIN DESCRIPTION (5)6.BLOCK DIAGRAM (6)7.FUNCTIONAL DESCRIPTION (7)7.1.Power Up and Initialization (7)7.2.Programming Mode Register (7)7.3.Bank Activate Command (7)7.4.Read and Write Access Modes (7)7.5.Burst Read Command (8)7.6.Burst Write Command (8)7.7.Read Interrupted by a Read (8)7.8.Read Interrupted by a Write (8)7.9.Write Interrupted by a Write (8)7.10.Write Interrupted by a Read (8)7.11.Burst Stop Command (9)7.12.Addressing Sequence of Sequential Mode (9)7.13.Addressing Sequence of Interleave Mode (9)7.14.Auto-precharge Command (10)7.15.Precharge Command (10)7.16.Self Refresh Command (10)7.17.Power Down Mode (11)7.18.No Operation Command (11)7.19.Deselect Command (11)7.20.Clock Suspend Mode (11)8.OPERATION MODE (12)9.ELECTRICAL CHARACTERISTICS (13)9.1.Absolute Maximum Ratings (13)9.2.Recommended DC Operating Conditions (13)9.3.Capacitance (13)9.4.DC Characteristics (14)9.5.AC Characteristics and Operating Condition (15)10.TIMING WAVEFORMS (17)mand Input Timing (17)10.2.Read Timing (18)10.3.Control Timing of Input/Output Data (19)10.4.Mode Register Set Cycle (20)11.OPERATING TIMING EXAMPLE (21)11.1.Interleaved Bank Read (Burst Length = 4, CAS Latency = 3) (21)11.2.Interleaved Bank Read (Burst Length = 4, CAS Latency = 3, Auto-precharge) (22)11.3.Interleaved Bank Read (Burst Length = 8, CAS Latency = 3) (23)11.4.Interleaved Bank Read (Burst Length = 8, CAS Latency = 3, Auto-precharge) (24)11.5.Interleaved Bank Write (Burst Length = 8) (25)11.6.Interleaved Bank Write (Burst Length = 8, Auto-precharge) (26)11.7.Page Mode Read (Burst Length = 4, CAS Latency = 3) (27)11.8.Page Mode Read / Write (Burst Length = 8, CAS Latency = 3) (28)11.9.Auto-precharge Read (Burst Length = 4, CAS Latency = 3) (29)11.10.Auto-precharge Write (Burst Length = 4) (30)11.11.Auto Refresh Cycle (31)11.12.Self Refresh Cycle (32)11.13.Burst Read and Single Write (Burst Length = 4, CAS Latency = 3) (33)11.14.Power Down Mode (34)11.15.Auto-precharge Timing (Read Cycle) (35)11.16.Auto-precharge Timing (Write Cycle) (36)11.17.Timing Chart of Read to Write Cycle (37)11.18.Timing Chart of Write to Read Cycle (37)11.19.Timing Chart of Burst Stop Cycle (Burst Stop Command) (38)11.20.Timing Chart of Burst Stop Cycle (Precharge Command) (38)11.21.CKE/DQM Input Timing (Write Cycle) (39)11.22.CKE/DQM Input Timing (Read Cycle) (40)12.PACKAGE SPECIFICATION (41)12.1.TFBGA 90 Balls pitch=0.8mm (41)13.REVISION HISTORY (42)1. GENERAL DESCRIPTIONW9812G2GB is a high-speed synchronous dynamic random access memory (SDRAM), organized as 1,048,576 words × 4 banks × 32 bits. Using pipelined architecture and 0.11 µm process technology, W9812G2GB delivers a data bandwidth of up to 166MHz words per second (-6). For different application, W9812G2GB is sorted into two speed grades: -6/-6I and -75. The –6 is compliant to the 166MHz/CL3 specification (the -6I grade which is guaranteed to support -40°C ~ 85°C). The -75 is compliant to the 133MHz/CL3 specification.Accesses to the SDRAM are burst oriented. Consecutive memory location in one page can be accessed at a burst length of 1, 2, 4, 8 or full page when a bank and row is selected by an ACTIVE command. Column addresses are automatically generated by the SDRAM internal counter in burst operation. Random column read is also possible by providing its address at each clock cycle. The multiple bank nature enables interleaving among internal banks to hide the precharging time.By having a programmable Mode Register, the system can change burst length, latency cycle, interleave or sequential burst to maximize its performance. W9812G2GB is ideal for main memory in high performance applications.2. FEATURES• 3.3V ± 0.3V Power Supply•Up to 166 MHz Clock Frequency• 1,048,576 Words × 4 banks × 32 bits organization• Self Refresh Mode•CAS Latency: 2 and 3•Burst Length: 1, 2, 4, 8 and full page•Burst Read, Single Writes Mode•Byte Data Controlled by DQM•Auto-precharge and Controlled Precharge•4K Refresh cycles / 64 mS• Interface: LVTTL•Packaged in TFBGA 90 Ball•W9812G2GB is using lead free materials with RoHS compliant3. AVAILABLE PART NUMBERPART NUMBER SPEEDMAXIMUM SELFREFRESH CURRENTOPERATINGTEMPERATUREW9812G2GB-6 166MHz/CL3 2mA 0°C ~ 70°C W9812G2GB-6I 166MHz/CL3 2mA -40°C ~ 85°C W9812G2GB-75 133MHZ/CL3 2mA 0°C ~ 70°C4. BALL CONFIGURATION5. PIN DESCRIPTION6. BLOCK DIAGRAM7. FUNCTIONAL DESCRIPTION7.1. Power Up and InitializationThe default power up state of the mode register is unspecified. The following power up and initialization sequence need to be followed to guarantee the device being preconditioned to each user specific needs.During power up, all V DD and V DDQ pins must be ramp up simultaneously to the specified voltage when the input signals are held in the “NOP” state. The power up voltage must not exceed V DD +0.3V on any of the input pins or V DD supplies. After power up, an initial pause of 200 µS is required followed by a precharge of all banks using the precharge command. To prevent data contention on the DQ bus during power up, it is required that the DQM and CKE pins be held high during the initial pause period. Once all banks have been precharged, the Mode Register Set Command must be issued to initialize the Mode Register. An additional eight Auto Refresh cycles (CBR) are also required before or after programming the Mode Register to ensure proper subsequent operation.7.2. Programming Mode RegisterAfter initial power up, the Mode Register Set Command must be issued for proper device operation. All banks must be in a precharged state and CKE must be high at least one cycle before the Mode Register Set Command can be issued. The Mode Register Set Command is activated by the low signals of RA,S CAS, CS and WE at the positive edge of the clock. The address input data during this cycle defines the parameters to be set as shown in the Mode Register Operation table. A new command may be issued following the mode register set command once a delay equal to t RSC has elapsed. Please refer to the next page for Mode Register Set Cycle and Operation Table.7.3. Bank Activate CommandThe Bank Activate command must be applied before any Read or Write operation can be executed. The operation is similar to RAS activate in EDO DRAM. The delay from when the Bank Activate command is applied to when the first read or write operation can begin must not be less than the RAS to CAS delay time (t RCD). Once a bank has been activated it must be precharged before another Bank Activate command can be issued to the same bank. The minimum time interval between successive Bank Activate commands to the same bank is determined by the RAS cycle time of the device (t RC). The minimum time interval between interleaved Bank Activate commands (Bank A to Bank B and vice versa) is the Bank to Bank delay time (t RRD). The maximum time that each bank can be held active is specified as t RAS (max).7.4. Read and Write Access ModesAfter a bank has been activated, a read or write cycle can be followed. This is accomplished by setting S RCD delay. WE pin voltage level RAS high and CA low at the clock rising edge after minimum of tdefines whether the access cycle is a read operation (WE high), or a write operation (WE low). The address inputs determine the starting column address.Reading or writing to a different row within an activated bank requires the bank be precharged and a new Bank Activate command be issued. When more than one bank is activated, interleaved bank Read or Write operations are possible. By using the programmed burst length and alternating the access and precharge operations between multiple banks, seamless data access operation amongmany different pages can be realized. Read or Write Commands can also be issued to the same bank or between active banks on every clock cycle.7.5. Burst Read CommandThe Burst Read command is initiated by applying logic low level to CS and CAS while holding RAS and WE high at the rising edge of the clock. The address inputs determine the starting column address for the burst. The Mode Register sets type of burst (sequential or interleave) and the burst length (1, 2, 4, 8 and full page) during the Mode Register Set Up cycle. Table 2 and 3 in the next page explain the address sequence of interleave mode and sequential mode.7.6. Burst Write CommandThe Burst Write command is initiated by applying logic low level to CS, CAS and WE while holding RAS high at the rising edge of the clock. The address inputs determine the starting column address. Data for the first burst write cycle must be applied on the DQ pins on the same clock cycle that the Write Command is issued. The remaining data inputs must be supplied on each subsequent rising clock edge until the burst length is completed. Data supplied to the DQ pins after burst finishes will be ignored.7.7. Read Interrupted by a ReadA Burst Read may be interrupted by another Read Command. When the previous burst is interrupted, the remaining addresses are overridden by the new read address with the full burst length. The data from the first Read Command continues to appear on the outputs until the CAS Latency from the interrupting Read Command the is satisfied.7.8. Read Interrupted by a WriteTo interrupt a burst read with a Write Command, DQM may be needed to place the DQs (output drivers) in a high impedance state to avoid data contention on the DQ bus. If a Read Command will issue data on the first and second clocks cycles of the write operation, DQM is needed to insure the DQs are tri-stated. After that point the Write Command will have control of the DQ bus and DQM masking is no longer needed.7.9. Write Interrupted by a WriteA burst write may be interrupted before completion of the burst by another Write Command. When the previous burst is interrupted, the remaining addresses are overridden by the new address and data will be written into the device until the programmed burst length is satisfied.7.10. Write Interrupted by a ReadA Read Command will interrupt a burst write operation on the same clock cycle that the Read Command is activated. The DQs must be in the high impedance state at least one cycle before the new read data appears on the outputs to avoid data contention. When the Read Command is activated, any residual data from the burst write cycle will be ignored.7.11. Burst Stop CommandA Burst Stop Command may be used to terminate the existing burst operation but leave the bank open for future Read or Write Commands to the same page of the active bank, if the burst length is full page. Use of the Burst Stop Command during other burst length operations is illegal. The Burst Stop Command is defined by having RAS and CAS high with CS and WE low at the rising edge of the clock. The data DQs go to a high impedance state after a delay which is equal to the CAS Latency in a burst read cycle interrupted by Burst Stop.7.12. Addressing Sequence of Sequential ModeA column access is performed by increasing the address from the column address which is input to the device. The disturb address is varied by the Burst Length as shown in Table 2.Table 2 Address Sequence of Sequential Mode7.13. Addressing Sequence of Interleave ModeA column access is started in the input column address and is performed by inverting the address bit in the sequence shown in Table 3.Table 3 Address Sequence of Interleave Mode7.14. Auto-precharge CommandIf A10 is set to high when the Read or Write Command is issued, then the auto-precharge function is entered. During auto-precharge, a Read Command will execute as normal with the exception that the active bank will begin to precharge automatically before all burst read cycles have been completed. Regardless of burst length, it will begin a certain number of clocks prior to the end of the scheduled burst cycle. The number of clocks is determined by CAS Latency.A Read or Write Command with auto-precharge can not be interrupted before the entire burst operation is completed. Therefore, use of a Read, Write or Precharge Command is prohibited during a read or write cycle with auto-precharge. Once the precharge operation has started, the bank cannot be reactivated until the Precharge time (t RP) has been satisfied. Issue of Auto-precharge command is illegal if the burst is set to full page length. If A10 is high when a Write Command is issued, the Write with Auto-precharge function is initiated. The SDRAM automatically enters the precharge operation two clocks delay from the last burst write cycle. This delay is referred to as Write t WR. The bank undergoing auto-precharge can not be reactivated until t WR and t RP are satisfied. This is referred to as t DAL, Data-in to Active delay (t DAL = t WR + t RP). When using the Auto-precharge Command, the interval between the Bank Activate Command and the beginning of the internal precharge operation must satisfy t RAS (min).7.15. Precharge CommandThe Precharge Command is used to precharge or close a bank that has been activated. The Precharge Command is entered when CS, RAS and WE are low and CAS is high at the rising edge of the clock. The Precharge Command can be used to precharge each bank separately or all banks simultaneously. Three address bits, A10, BS0, and BS1, are used to define which bank(s) is to be precharged when the command is issued. After the Precharge Command is issued, the precharged bank must be reactivated before a new read or write access can be executed. The delay between the Precharge Command and the Activate Command must be greater than or equal to the Precharge time (t RP).7.16. Self Refresh CommandThe Self Refresh Command is defined by having CS, RAS, CAS and CKE held low with WE high at the rising edge of the clock. All banks must be idle prior to issuing the Self Refresh Command. Once the command is registered, CKE must be held low to keep the device in Self Refresh mode. When the SDRAM has entered Self Refresh mode all of the external control signals, except CKE, are disabled. The clock is internally disabled during Self Refresh Operation to save power. The device will exit Self Refresh operation after CKE is returned high. A minimum delay time is required when the device exits Self Refresh Operation and before the next command can be issued. This delay is equal to the t AC cycle time plus the Self Refresh exit time.If, during normal operation, AUTO REFRESH cycles are issued in bursts (as opposed to being evenly distributed), a burst of 4,096 AUTO REFRESH cycles should be completed just prior to entering and just after exiting the self refresh mode. The period between the Auto Refresh command and the next command is specified by t RC.7.17. Power Down ModeThe Power Down mode is initiated by holding CKE low. All of the receiver circuits except CKE are gated off to reduce the power. The Power Down mode does not perform any refresh operations, therefore the device can not remain in Power Down mode longer than the Refresh period (t REF) of the device.The Power Down mode is exited by bringing CKE high. When CKE goes high, a No Operation Command is required on the next rising clock edge, depending on t CK. The input buffers need to be enabled with CKE held high for a period equal to t CKS (min) + t CK (min).7.18. No Operation CommandThe No Operation Command should be used in cases when the SDRAM is in a idle or a wait state to prevent the SDRAM from registering any unwanted commands between operations. A No Operation Command is registered when CS is low with RAS, CAS, and WE held high at the rising edge of the clock. A No Operation Command will not terminate a previous operation that is still executing, such as a burst read or write cycle.7.19. Deselect CommandThe Deselect Command performs the same function as a No Operation Command. Deselect Command occurs when CS is brought high, the RAS, CAS, and WE signals become don’t cares.7.20. Clock Suspend ModeDuring normal access mode, CKE must be held high enabling the clock. When CKE is registered low while at least one of the banks is active, Clock Suspend Mode is entered. The Clock Suspend mode deactivates the internal clock and suspends any clocked operation that was currently being executed. There is a one clock delay between the registration of CKE low and the time at which the SDRAM operation suspends. While in Clock Suspend mode, the SDRAM ignores any new commands that are issued. The Clock Suspend mode is exited by bringing CKE high. There is a one clock cycle delay from when CKE returns high to when Clock Suspend mode is exited.8. OPERATION MODEFully synchronous operations are performed to latch the commands at the positive edges of CLK. Table 1 shows the truth table for the operation commands.Table 1 Truth Table (Note (1), (2))Notes:(1) v =valid x =Don’t care L =Low Level H =High Level(2) CKEn signal is input level when commands are provided.CKEn-1 signal is the input level one clock cycle before the command is issued.(3) These are state of bank designated by BS0, BS1 signals.(4) Device state is full page burst operation.(5) Power Down Mode can not be entered in the burst cycle.When this command asserts in the burst cycle, device state is clock suspend mode.9. ELECTRICAL CHARACTERISTICS9.1. Absolute Maximum RatingsRATINGUNIT PARAMETER SYMBOLInput/Output Voltage V IN, V OUT -0.3 ~ V DD +0.3 VPower Supply Voltage V DD, V DDQ-0.3 ~ 4.6 VOperating Temperature (-6/-75) T OPR0 ~ 70 °C°C85Operating Temperature (-6I) T OPR -40~°C150Storage Temperature T STG -55~Soldering Temperature (10s) T SOLDER 260 °CW Power Dissipation P D 1mA Short Circuit Output Current I OUT 50Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability of the device.9.2. Recommended DC Operating Conditions(Ta = 0 to 70°C for -6/-75, Ta= -40 to 85°C for -6I)UNIT PARAMETER SYMBOL MIN.MAX.TYP.Power Supply Voltage V DD 3.0 3.3 3.6 VPower Supply VoltageV DDQ 3.0 3.3 3.6 V(for I/O Buffer)V DD +0.3 VInput High Voltage V IH 2.0 -Input Low Voltage V IL -0.3 - 0.8 VNote: V IH(max) = V DD/ V DDQ+1.2V for pulse width < 5 nSV IL(min) = V SS/ V SSQ-1.2V for pulse width < 5 nS9.3. Capacitance(V DD= 3.3V, f = 1 MHz, Ta 25°C)Note: These parameters are periodically sampled and not 100% tested.9.4. DC Characteristics(VDD =3.3V± 0.3V, Ta = 0 to 70°C for-6/-75, Ta= -40 to 85°C for -6I)NOTESUNIT PARAMETER SYMBOL MIN.MAX.Input Leakage CurrentI I(L) -5 5 µA (0V ≤V IN≤ V DD, all other pins not under test = 0V)Output Leakage CurrentI O(L) -5 5 µA (Output disable , 0V ≤ V OUT≤ V DDQ)LVTTL Output ″H″ Level VoltageV OH 2.4 - V(I OUT = -2 mA )LVTTL Output ″L″ Level VoltageV OL - 0.4 V(I OUT = 2 mA )9.5. AC Characteristics and Operating Condition(VDD =3.3V ± 0.3V, Ta = 0 to 70°C for -6/-75, Ta= -40 to 85°C for -6I, Notes: 5, 6, 7, 8, 9, 10)-6/-6I -75PARAMETER SYM.MIN. MAX. MIN. MAX.UNIT NOTESRef/Active to Ref/Active Command Period t RC 60 65 Active to precharge Command Period t RAS 42 10000045 100000 nSActive to Read/Write Command Delay Timet RCD 18 20 Read/Write(a) to Read/Write(b) Command Periodt CCD 1 1 t CKPrecharge to Active Command Period t RP 18 20 Active(a) to Active(b) Command Period t RRD 12 15 nS CL* = 2 22 t CKWrite Recovery Time CL* = 3 t WR 22CL* = 2 101000101000CLK Cycle TimeCL* = 3t CK6 1000 7.5 1000CLK High Level widtht CH 2 2.5 9 CLK Low Level widtht CL 2 2.59CL* = 2 6 6 Access Time from CLKCL* = 3t AC 5 5.4 10 Output Data Hold Timet OH 3 3 10 Output Data High Impedance Time t HZ 3 6 3 7.5 8 Output Data Low Impedance Time t LZ 0 0 10 Power Down Mode Entry Time t SB 0 6 0 7.5Transition Time of CLK (Rise and Fall) t T 0.1 1 0.1 1 7 Data-in Set-up Time t DS 1.5 1.5 9 Data-in Hold Time t DH 1.0 1.0 9 Address Set-up Time t AS 1.5 1.5 9 Address Hold Time t AH 1.0 1.0 9 CKE Set-up Time t CKS 1.5 1.5 9 CKE Hold Time t CKH 1.0 1.0 9 Command Set-up Time t CMS 1.5 1.5 9 Command Hold Time t CMH 1.0 1.0nS9Refresh Timet REF 64 64 mS Mode register Set Cycle Time t RSC 12 15 nS Exit self refresh to ACTIVE commandt XSR72 75 nS*CL = CAS LatencyNotes:1. Operation exceeds “Absolute Maximum Ratings” may cause permanent damage to the devices.2. All voltages are referenced to V SS3. These parameters depend on the cycle rate and listed values are measured at a cycle rate with the minimum values of t CK and t RC .4. These parameters depend on the output loading conditions. Specified values are obtained with output open.5. Power up sequence is further described in the “Functional Description” section.6. AC Testing ConditionsPARAMETER CONDITIONSOutput Reference Level1.4VOutput LoadSee diagram belowInput Signal Levels (V IH /V IL ) 2.4V/0.4VTransition Time (t T : tr/tf) of Input Signal 1/1 nS Input Reference Level 1.4V7. Transition times are measured between V IH and V IL .8. t HZ defines the time at which the outputs achieve the open circuit condition and is not referenced to output level.9. Assumed input transition Time (t T ) = 1nS.If tr & tf is longer than 1nS, transient time compensation should be considered, i.e., [(tr + tf)/2-1]nS should be added to the parameter(The t T maximum can’t be more than 10nS for low frequency application.)10. If clock rising time (t T ) is longer than 1nS, (t T /2-0.5)nS should be added to the parameter.10. TIMING WAVEFORMS 10.1. Command Input Timing10.2. Read Timing10.3. Control Timing of Input/Output Data10.4. Mode Register Set Cycle11. OPERATING TIMING EXAMPLE11.1. Interleaved Bank Read (Burst Length = 4, CAS Latency = 3)11.2. Interleaved Bank Read (Burst Length = 4, CAS Latency = 3, Auto-precharge)11.3. Interleaved Bank Read (Burst Length = 8, CAS Latency = 3)11.4. Interleaved Bank Read (Burst Length = 8, CAS Latency = 3, Auto-precharge)11.5. Interleaved Bank Write (Burst Length = 8)11.6. Interleaved Bank Write (Burst Length = 8, Auto-precharge)11.7. Page Mode Read (Burst Length = 4, CAS Latency = 3)11.8. Page Mode Read / Write (Burst Length = 8, CAS Latency = 3)11.9. Auto-precharge Read (Burst Length = 4, CAS Latency = 3)11.10. Auto-precharge Write (Burst Length = 4)11.11. Auto Refresh Cycle11.12. Self Refresh Cycle11.13. Burst Read and Single Write (Burst Length = 4, CAS Latency = 3)11.14. Power Down Mode11.15. Auto-precharge Timing (Read Cycle)11.17. Timing Chart of Read to Write Cycle11.18. Timing Chart of Write to Read Cycle11.19. Timing Chart of Burst Stop Cycle (Burst Stop Command)11.20. Timing Chart of Burst Stop Cycle (Precharge Command)11.21. CKE/DQM Input Timing (Write Cycle)11.22. CKE/DQM Input Timing (Read Cycle)12. PACKAGE SPECIFICATION12.1. TFBGA 90 Balls pitch=0.8mmPublication Release Date:Aug. 13,2007- 41 - Revision A07Publication Release Date: Aug. 13,2007- 42 - Revision A0713. REVISION HISTORYVERSION DATEPAGEDESCRIPTIONA01 Mar. 24, 2006 All Create new datasheet A02 Jul. 05, 2006 8 Burst Stop commandA03 Sep. 08, 2006 10 Exit Auto refresh to next command is specified by t RC A04 Sep. 27, 200615,16Modify Characteristics Notes 9 and add Notes 10 (t T ) A05 Apr. 12, 2007 15,32,34,41Add t XSR timing specification and package dimension ball openingA06 Jun. 21, 2007 3,13,14,15Add -6I gradeA07 Aug. 13, 200716Revise transient time t T AC test condition and calculate formula for compensation consideration in Notes 6, 9 of AC Characteristics and Operating ConditionImportant NoticeWinbond products are not designed, intended, authorized or warranted for use as components in systems or equipment intended for surgical implantation, atomic energy control instruments, airplane or spaceship instruments, transportation instruments, traffic signal instruments, combustion control instruments, or for other applications intended to support or sustain life. Further more, Winbond products are not intended for applications wherein failure of Winbond products could result or lead to a situation wherein personal injury, death or severe property or environmental damage could occur.Winbond customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Winbond for any damages resulting from such improper use or sales.。

Chapter26首先查看相关汇编指令的含义：选项含义：26.1答：首先查看loop.s文件内容如下：运行以上命令，得到以下结果：使用“-c”选项运行命令查看答案，结果和上图一致，说明分析正确。

26.2答：分析以上命令可知“-t2”表示指定两个线程，“-i100”表示中断间隔为100，“-a dx=3，dx=3”表示指定线程0和线程1的dx均初始化为3，运行以上命令得以下运行结果：使用“-c”选项运行命令查看答案，结果和上图一致，说明分析正确。

26.3答：分析以上命令可知，相对第二题，该命令只是将中断间隔由原来的100改为3，运行以上命令得到以下运行结果：（此结果为-s为0）使用“-c”选项运行命令查看答案，结果和上图一致，说明分析正确。

再对“-s”的值进行改变和运行，查看结果可知不同的种子情况下运行结果一致。

由本实验可知中断频率会改变程序的行为。

26.4答：首先查看并分析looping-race-nolock.s文件的内容如下图：运行以上命令得到以下结果：使用“-c”选项运行命令查看答案，结果和上图一致，说明分析正确。

Chapter28首先查看选项明确含义，大多数的选项与Chapter26的相同，主要有以下新选项：28.1答：首先查看flag.s文件内容：运行命令得以下结果：由上图可知，首先是线程0获得锁，直到执行结束释放锁之后线程1才获得锁并执行。

由此可分析以上汇编代码是想通过用一个变量来标志锁是否被某些线程占用。

第一个线程到达时首先会检查标志是否为0，如果是0则设置标志为1表示已经获得锁，其他线程到达时如果第一个线程仍未执行结束则一直检查标志是否为0，直到第一个线程执行结束释放锁（将标志设置为0）才会被其他线程获取。

28.2答：有第一题可得，使用默认值运行时，flag.s可按预期工作。

可以产生正确的结果，并且可以预测代码运行时最终的flag标志会被置0，因为线程1执行结束后锁会被释放。

使用-M和-R对相应的地址内存和寄存器进行跟踪，运行一下命令“./x86.py-p flag.s-R ax,bx-M flag,count-c”，运行结果如下图：28.3答：在第二题的命令的基础上加上-a选项“-a bx=2,bx=2”再次运行，结果如下。

[RCUstall]RCUstall分析，RCUstall内核⽂档翻译使⽤RCU的CPU失速检测器本⽂档⾸先讨论RCU的CPU停顿检测器可以定位哪些问题，然后讨论可⽤于微调检测器操作的内核参数和Kconfig选项。

最后，本⽂解释了失速检测器的“splat”格式。

是什么导致RCU CPU停顿警告？是因为您的内核会打印RCU CPU停⽌警告。

下⼀个问题是“是什么原因引起的？” 以下问题可能导致RCU CPU停顿：警告：o RCU read-side 关键部分中出现CPU循环。

o 禁⽤中断时出现CPU循环。

o 禁⽤抢占时出现CPU循环。

这种情况可能会导致RCU调度的停顿，并且，如果使⽤kso??ftirqd，则会导致RCU-bh停顿。

o 下半部禁⽤时出现CPU循环。

这种情况可能导致RCU调度和RCU-bh停顿。

o 对于!CONFIG_PREEMPT内核,CPU可以在内核中的任何位置循环,⽽⽆需调⽤schedule()。

如果确实确实希望在内核中循环,这是您期望的⾏为,则可能需要向cond_resched()添加⼀些调⽤。

o 使⽤太慢的控制台连接来引导Linux,以致⽆法跟上引导时控制台消息的速率。

例如,115Kbaud串⾏控制台的速度可能太慢⽽⽆法跟上启动时消息的速率,经常会导致RCU CPU停顿警告消息。

特别是如果您添加了printk()调试代码。

o 阻⽌RCU宽限期kthread运⾏的任何措施。

这可能会导致“All QSes seen”控制台⽇志消息。

此消息将包含有关kthread上次运⾏的时间以及应该运⾏的频率的信息。

它还可能导致控制台⽇志消息“ rcu _.*kthread starved for”，其中将包含其他调试信息。

O CONFIG_PREEMPT内核中的CPU绑定的实时任务，这可能恰好抢占了RCU读取侧关键部分中间的低优先级任务。

如果不允许该低优先级任务在任何其他CPU上运⾏，则这尤其有害，在这种情况下，下⼀个RCU宽限期将永远⽆法完成，最终将导致系统内存不⾜并挂起。

gostub函数打桩-回复如何使用gostub函数进行打桩。

标题：使用gostub函数进行打桩：完美解决单元测试中的外部依赖问题引言：在软件开发过程中，我们经常面临一个共同的问题：如何在单元测试中处理对外部依赖的调用，以确保测试的可靠性和可重复性。

传统的方法往往是使用模拟对象或者模拟框架，但是这些方法要么过于复杂，要么效率低下。

幸运的是，在Go语言中，我们有一个简单而高效的解决方案——gostub函数。

第一步：了解gostub函数的基本概念gostub函数是一个基于反射的库，专门用于在单元测试中处理外部依赖。

它的原理是通过打桩（stubbing）的方式，将被测试函数中的外部依赖替换为自定义的实现，以便进行测试。

具体来说，gostub函数通过修改函数的符号表，来劫持外部函数的调用，从而实现打桩的效果。

第二步：安装gostub函数库在开始使用gostub函数之前，我们首先需要将它添加到我们的Go项目中。

打开终端，使用以下命令安装gostub函数库：bashgo get github/prashantv/gostub这个命令将会自动从GitHub上下载最新版本的gostub函数库，并将它安装到你的GOPATH目录下。

第三步：创建一个需要进行测试的函数在我们使用gostub函数之前，我们需要先创建一个带有外部依赖的函数，作为我们将要进行测试的对象。

这个函数可以是一个已经存在的函数，也可以是一个你自己定义的函数。

以下是一个简单的示例：gopackage mathimport "strconv"func Add(a, b int) (int, error) {sum := a + bstr, err := externalService(strconv.Itoa(sum)) if err != nil {return 0, err}result, err := strconv.Atoi(str)if err != nil {return 0, err}return result, nil}上面的示例函数中，我们使用了一个外部的服务externalService，这个服务接受一个整型参数，并返回一个字符串。

南京O r a c l e认证培训T i m e s T e n学习之安装篇南京Oracle认证培训 TimesTen学习之安装篇一.Linux平台安装准备工作。

1.大页设置1).修改HugePage配置值：echo 32 > /proc/sys/vm/nr_hugepages2).查看HugePage值：[root@ttdb ~]# cat /proc/meminfo | grep HugeHugePages_Total: 28HugePages_Free: 28HugePages_Rsvd: 0Hugepagesize: 2048 kB2.信号量1).查看当前值：[root@ttdb ~]# /sbin/sysctl -a | grep semkernel.sem = 250 32000 32 1282).推荐值：kernel.sem = 400 32000 100 1283).使设置生效：/sbin/sysctl -p3.共享内存kernel.shmmax=2147483648（单位：字节byte）。

如果配置大于8GB，那么也应该增加shmall参数的值，这个值应该等于SHMMAX/PAGE_SIZE,在x86系统Page的大小通常为4K，在安腾平台通常为16K，例如，在安腾64GB的数据库，应该指定以下的参数值：kernel.shmmax=68719476736kernel.shmall=41943041).配置shmmax和shmall参数：在没有重启的情况下，执行以下的命令修改共享内存的值：/sbin/sysctl -w kernel.shmmax=2147483648也可以通过以下命令修改这个值：echo 2147483648 > /proc/sys/kernel/shmmax这个命令与执行sysctl命令有相同的效果。

2).查看共享内存值：cat /proc/sys/kernel/shmmax注意：如果操作系统使用的是Redhat，从Redhat Enterprise 5.4开始，shmmax和shmall 这两个值已经足够的大，默认不需要修改。

MVTS安装使用说明（适用310 312）第一节，安装操作系统要求：310 运行在LINUX AS3或ES3 以下的版本312运行在LINUX Radhat 9.0以上版本，（不包括LINUX9.0）建议硬件配置：CPU：P4 2.0以上内存：2G以上硬盘：30G以上安装步骤：安装linux完成后，将MVTS的manager.tar.gz和MVTS-310-Linux.tar.gz两个安装包上传到/usr/local 目录下.使用SSH登陆LINUX，执行以下命令：cd /usr/loca 回车tar -zxvf MVTS-310-Linux.tar.gz 回车tar –zxvf manager.tar.gz 回车cd mvts 回车[root@localhost mvts]# sh setup.shMVTS installation:enter MVTS admin group id:0 输入0回车enter MVTS support group id:0 输入0回车enter MVTS billing group id:0 输入0回车updating ./cfg/meraproxy.cfg ...setting permissions to MVTS contents ...updating /etc/profile ...making startup script mvts ...moving startup script to /etc/rc.d/init.d ...adding links for start/stopcreate links:/etc/rc.d/init.d/mvts <- /etc/rc.d/rc5.d/S50mvts/etc/rc.d/init.d/mvts <- /etc/rc.d/rc0.d/K50mvtsinstallation successful这样MVTS就安装好了，这个时候还不能登陆，需要安装managercd ..回车cd manager 回车sh setupMVTS directory? [/usr/local/mvts]: /root/mvtsMVTS Manager directory? [/root/mvts/manager]: 回车MVTS admin group? [mvts]: 回车Group mvts does not exist. Create? [y/n]: yMVTS admin user (not root)? [mvts]: 回车User mvts does not exist. Create? [y/n]: yChanging password for user mvts.New password: 密码写入linux的密码BAD PASSWORD: it is too shortRetype new password: 密码写入linux的密码passwd: all authentication tokens updated successfully.MVTS Manager successfully installed.Please do following steps before using MVTS Manager:1. Edit file /root/mvts/cfg/meraproxy.cfg:[Console]console_port=1730admin_gid=5012. Reload MVTS configuration:/root/mvts/bin/mp_shell.x r c -d3. Start MVTS agent from root:/root/mvts/manager/bin/mvtsagntctl startor/etc/init.d/mvtsagnt startThank you for using MVTS Manager![root@localhost manager]# /etc/init.d/mvtsagnt startStarting MVTS Agent: [ OK ]Manager 安装最好装两次，也就是执行2次sh setup 确保能安装成功请注意以上的红色，那写请按上面的中文提示作相应操作，安装完成后先别急着启动请注意这段提示：1. Edit file /root/mvts/cfg/meraproxy.cfg:[Console]console_port=1730admin_gid=501这里也要做相应修改写入vi /root/mvts/cfg/meraproxy.cfg回车找到后面这个按A作相应修改：console_port=1730admin_gid=501修改好后按ESC退出编辑命令，再输入wq! 保存退出以下命令是用来启动和停止MVTS的起动MVTS: /etc/init.d/mvts start停止MVTS: /etc/init.d/mvts stop起动mvtsagnt: /etc/init.d/mvtsagnt start停止mvtsagnt: /etc/init.d/mvtsagnt stop安装完成后第二节：MVTS的登陆和相关功能按键介绍请在你的电脑上安装MVTS的管理软件MVTSmanager并运行manager软件看到以上窗口说明MVTSmanager成功运行了，这个时候我们要做登陆服务器的数据:点右边的Create 看到如下窗口:写入相关数据，MVTS刚安装的默认登陆端口是1730 帐号和密码是admin 都是小写，小提示:MVTS的数据里面不可以存在全角字符更不能有中文，不然是不能登陆的.写完后点OK就保存下来了，然后选中他双击或点右上解的OK，即可连接，连接的过程会有点慢，请耐心等待，出现如下窗口后即说明成功登陆了:本文重点介绍如何对接IP认证客户和、注册用户、和落地对接路由方式←落地对接和网关对接都是在这里←路由调度在这里←注册帐号类型Originators 是指用户的帐号品质报告Terminators 是指落地的品质报告Gteways 是指所有在Gateways的品质报告Dialpeers是指路由调度的品质报告Endpoints 这里显示RAS 注册帐号的在线状态Active Calls是指当前在线的活动呼叫CDR 显示最近100条目的是用来查线路的问题Edit Config 编辑模式，要作数据改动，必须进入此模式（同时只能一人在线）Cancel edit 撤消编辑并退出。

kgdb内核调试原理
kgdb内核调试原理基于以下步骤：
1. kgdb在Linux内核中添加一个调试stub，这是内核中的一小段代码，充当运行gdb的开发机和目标机内核之间的媒介。

2. gdb和调试stub之间通过gdb串行协议进行通信，这是一种基于消息的ASCII码协议，包含了各种调试命令。

3. 当设置断点时，kgdb将断点的指令替换为一条trap指令。

当执行到断点时，控制权就转移到调试stub中去。

4. 调试stub的任务是使用远程串行通信协议将当前内核环境传送给gdb，然后从gdb处接收命令。

5. kgdb本身运行在内核空间，可以访问内核空间或者用户空间，获取相应的被调试程序的数据信息。

6. 在连接通信过程中，target运行配置了kgdb的内核，host运行gdb，中间使用RSP协议进行通信。

gdb向kgdb发送RSP命令包，kgdb解析命令包，从而实现target的内核调试。

以上是kgdb内核调试的基本原理，如需更深入了解其工作原理，建议查阅相关的技术文档或咨询专业技术人员。

slurm任务调度系统部署和测试（⼀）1.概述本博客通过VMware workstation创建了虚拟机console，然后在console内部创建了8台kvm虚拟机，使⽤这8台虚拟机作为集群，来部署配置和测试slurm任务调度系统。

console虚拟机配置为：4核⼼CPU，8G内存，20G系统盘安装OS，20G数据盘挂载到/opt，10G数据盘挂载到/home，⼀块NAT⽹卡模拟带外，⼀块Host only⽹卡模拟专⽤内⽹在使⽤console部署8台kvm虚拟机之后，需要做⼀下操作：部署console到node11-18的免密码登陆，通过sshpass+shell实现部署console为NTP服务器，同步node11-18的时间到console部署console为LDAP服务器，能够实现全局⽤户认证格式化数据盘，将/opt和/home通过NFS共享给node11-18注：上⾯这部分内容涉及较多，如VMware workstation部署虚拟机console，console虚拟机部署kvm虚拟机，创建并挂载NFS全局⽂件系统，console到多节点的免密码登陆，NTP和LDAP服务部署等，这⾥不做⼀⼀详述。

2.同步时间节点将console部署为NTP服务器之后，通过定时执⾏同步任务来保证所有节点时间⼀致：pdsh -w node[11-18] ntpdate 192.168.80.8将该命令写⼊定时任务：crontab -e*/5 * * * * pdsh -w node[11-18] "ntpdate 192.168.80.8; hwclock --systohc"3.下载软件包munged-0.5.12slurm-16.05.3（该软件包因为安全漏洞问题，已经⽆法下载，可下载其他版本）4.编译安装munge-0.5.121.创建安装⽬录：mkdir -p /opt/munge/munge-0.5.122.解压：unzip munge-munge-0.5.12.zip3.编译：cd munge-munge-0.5.12./configure --prefix=/opt/munge/munge-0.5.12 --sysconfdir=/opt/munge/munge-0.5.12/etc --localstatedir=/varmake && make install注：此时编译报错：checking which cryptographic library to use... failedconfigure: error: unable to locate cryptographic library解决如下：yum -y install openssl openssl-devel此时可以在/opt/munge/munge-0.5.12下，查看到munge的各类⽬录5.配置munge我希望munged在运⾏的时候，以root⽤户的⾝份运⾏（默认是munge⽤户），此时需要修改配置。

Platform Support Package DetailsThe Impulse C Platform Support Package (PSP) “Xilinx Open Source Linux Virtex-5 APU” has been adapted from the Virtex-5 APU PSP. The HDL hardware side is unchanged from the original, standalone PSP; only the software side is modified in support of embedded Linux. An alternate “Xilinx Open Source Linux Virtex-4 APU” PSP is also ready to use with Virtex-4 FPGA devices.This tutorial assumes that you have some knowledge of Impulse C, and of the Xilinx Virtex-5 FX devices. Experience with creating standalone Impulse C applications (with no embedded Linux) on the Xilinx ML507 or equivalent board is also helpful.In the standalone mode APU PSP, co_streams are implemented using Xilinx APU specific in structions “stwfcmx” and “lwfcmx”. When running Linux over PowerPC, we replace these instructions with Altivec extended instructions “stvewx” and “lvewx”.In co_stream.c, the functions “co_stream_read”, “co_stream_write” and“co_stream_close” are supporte d. The p rimitives “HW_STREAM_READ”,“HW_STREAM_WRITE” and “HW_STREAM_CLOSE” are supported as well.When the PowerPC CPU runs applications in standalone mode, the application software can have privileged instructions, such as “mtmsr” to enable the APUon the MSR register. When an application runs on Linux user space, however,the “mtmsr” instruction is not allowed. Here, then, we must modify somekernel code to allow the APU to work.In the directory “linux-2.6- xlnx/arch/powerpc/include/asm”, you mustmo dify header files “reg.h” and “reg_booke.h” as follows:----- reg.h -------#ifdef CONFIG_PPC64.......#else /* 32-bit *//* Default MSR for kernel mode. */#ifndef MSR_KERNEL /* reg_booke.h also defines this */#define MSR_KERNEL (MSR_ME|MSR_RI|MSR_IR|MSR_DR|MSR_VEC)#endif----- reg_booke.h ---------/* Default MSR for kernel mode. */#if defined (CONFIG_40x)#define MSR_KERNEL(MSR_ME|MSR_RI|MSR_IR|MSR_DR|MSR_CE|MSR_VEC)#elif defined(CONFIG_BOOKE)#define MSR_KERNEL (MSR_ME|MSR_RI|MSR_CE|MSR_VEC)#endif------The basic idea is to add the “MSR_VEC” bit to “MSR_KERNEL” for APU activation.In the PSP, “export.tcl” has been modified so that a new directory “user_app” is constructed, and application code is copied into it. The EDK/code directory is no longer included, since the source files won’t be needed in EDK. The necessary Impulse library source files are being copied to the sub-directory “libImpulse” with a Makefile. “genMakefile.tcl” is added to the PSP, so that a Makefile for the software application is generated and copied into the“user_app” folder.You need to go to the “user_app/libImpulse” directory to build the Imp ulse library, and then go up to the “user_app” directory to build your software application. A Makefile is already g enerated for you, so just a “make” command will do the job.In “co.h”, LINUX is defined, so that in user code, the compiler knows when to select the Linux related code.Software Application Development NotesCurrently, the XOSL APU PSP only supports co_streams forhardware/software communications. The HW_STREAM_READ,HW_STREAM_WRITE and HW_STREAM_CLOSE primitives are recommended in software-side coding for higher efficiency and thus faster execution time.The user C code is being built using cross compiler Denx EDLK toolchain “ppc_4xx-gcc”. If your code previously runs in standalone mode, and you want to adapt it to run on Linux, you need to eliminate all the Xilinx-related functions and header files, and replace them with Linux ones. Also, sinceyour a pplication runs in user mode, don’t use any privilege mode asm instructions, such as “mtmsr”.XOSL Development Environment SetupBuilding applications for Xilinx embedded Linux requires a Linux development environment. You can either use a dedicated Linux computer for this purpose, or use a virtual machine. For this project, I chose to download CentOS 5.2 as my Linux OS, running it on a VMware virtual machine. Any Linux 2.6 system will work.“git” is needed for installing XOSL. You can install it as fol lows:su -c 'rpm -Uvh /pub/epel/5/i386/epel-release-5-3.noarch.rpm'su -c 'yum -y install git'You may need to install “ncurses” for using menuconfig.yum -y install ncurses-develThe XOSL information is available online at /open-source-linux.To clone the Xilinx Linux Kernel tree run:git clone git:///linux-2.6-xlnx.gitAlso, clone the device tree bsp using git:git clone git:///device-tree.gitCopy the device-tree to the following directory on your PC:[Xilinx Installation Directory]\10.1\EDK\sw\ThirdParty\bspThe EDK runs on Windows, so we need to mount a windows share folder on the Linux machine for sharing documents between your Linux machine and windows PC.mount -t cifs //[IP address of the Windows host]/[folder name] [/dir in Linux machine] -o usernam e=[xxx],password=[***]You need to download a cross compiler for PowerPC, such as DENX_ELDK. You can download ISO image ppc-2008-04-01_amcc.iso using FTP from site ftp.sunet.se at /pub/Linux/distributions/eldk/4.2/ppc-linux-x86/iso/.To mount ISO:sumkdir /mnt/isomount m yiso.iso /mnt/iso/ -t iso9660 -o ro,loop=/dev/loop0To install:cd /m nt/iso./install -d /hom e/meixu/Xlinx/DENK_ELDK ppc_4xxTo set path and environment variable:PATH=/home/meixu/Xlinx/DENX_ELDK/usr/b in:/home/meixu/Xlinx/DENX_ELDK/bin: $PATH --let the ELDK/usr/bin dir first to use the new binutils.export CROSS_COMPILE=ppc_4xx-Using CoDeveloper to Generate Hardware and SoftwareCopy the ComplexFIR project folder “ComplexFIR_XOSL_PPC440” to your windows share directory. Open the project in CoDeveloper Application Manager.Open the Project Options Dialogue, and choose “Xilinx Open Source Linux Virtex-5 APU (VHDL)” as the Platform Support Package. Checking the “Generate dual clock” will allow the Impulse hardware module to use adifferent clock other than the APU clock of PowerPC.Next, generate HDL code by clicking the “HDL” button below:Export the generated hardware to designated directory “EDK” by clicking the“HW” button.Export the generated software by clicking the “SW” button.The directory structure is shown below. The HDL code and drivers are in the “EDK” directory. Software code is in the “user_app” directory.In next step, we use Xilinx Platform Studio to build a PowerPC system with the generated Impulse module.Create a new XPS project in the “EDK” directory above. In Base System Builder (BSB), select Xilinx ML507 as the development platform.Select PowerPC as the processor.Next, choose processor clock to be 400 MHz, and bus clock 100 MHz. Enable cache, and disable the FPU.In IO configuration, select device RS232_Uart_1 with type XPS UART 16550, and check “Use interrupt”.Unselect the RS232_Uart_2 and the LEDs_8Bit.On the next page, select the IIC_EEPROM only.Next, select the FLASH and the PCIe_Bridge devices.Select the DDR2_SDRAM and the SysACE_CompactFlash.Next, enlarge the memory si ze of XPS BRAMs to 64 KB.Add a peripheral “xps_timer_1” to the system. Choose one timer mode, and use interrupt.Next, select the cache opti ons.On the next page, select the sample applications as you wish.Next, click OK to accept memory settings for the sample applications.A page of design summary appears. Click “generate” to build the system.Here is the bus interface view of the PowerPC system you just built:In order to use the APU feature, we need to add a Fabric Co-processor Bus to the system.Next, add the Impulse generated module apu_filt from the Project Local pcores\USER.Next, connect the FCB bus to both ppc440_0 and apu_filt_0 as shown below:Open the “Clock Generator” window by double-clicking the moduleclock_genrator_0. Add another clock output “pcore_co_clk” of frequency 33.333333 MHz as shown below.In the “Ports” tab, connect the reset and clock ports of fcb_v20_0.And connect the co_clk and apu_clk ports of apu_filt_0 as shown below.Double-click the ppc440_0 to open the dialogue below. In the APU tab, set the APU Controller Configuration Register Value to 0b0010010000100001.Next, go to the Addresses tab, and generate addresses for the system.O pen the Software Platform Settings Dialogue. Select “device-tree” as the OS.In the OS and Libraries view, type “RS232_Uart_1” as the console device, and “console=ttyS0 root=/dev/ram rw ip=off” as the bootargs.Next, click Software → Generate Libraries and BSPs. This will create a file “Xilinx.dts” in directory EDK\ppc440_0\libsrc\device-tree.Rename the DTS file to virtex440-ml507.dts, and copy it to linux-2.6-xlnx/arch/powerpc/boot/dts/Go back to XPS, Hardware → Generate Bitstream. This will take 10 minutes or more to finish, depending on your PC speed.In the Applications Tab, select the ppc440_0_bootloop as the application for initializing BRAMs.Building the XOSL OS and File System on the Linux MachineGo to the XOSL main directory: linux-2.6-xlnxmake ARCH=powerpc 44x/virtex5_defconfigmake ARCH=powerpc m enuconfigMake changes to the following options:∙Kernel options → Initial kernel command string: console=ttyS0 boot=/dev/ram rw ip=off∙File systems → Ext3 journalling file system support∙Device Dirvers → Block devices → Xilinx systemACE support∙Exit and save changes.Next, download “ramdisk.image.gz” from /open-source-linux. At the end of the page, click “files”, and a list of downloadable files will show. Copy the file to your windows share folder “win_share_5”. Switch to the user_app directory:win_share-5/ComplexFIR_XOSL_PPC440/user_appUser application source files and a Makefile are in the user_app folder. The Impulse library source files and a Makefile are in the libImpulse subdirectory. Use command “make” to build the Impulse library “libImpulse.a”, and in the user_app directory, use command “make” to build the executable file “filt”.For the purpose of easy operation, I create a shell script “makeDiskComplexFIR.sh” to add the ComplexFIR software application into the ramdisk and then build the XOSL system.gunzip ramdisk.image.gzmount -o loop ramdisk.image tem prm temp/t m p/*cp ComplexFIR_XOSL_PPC440/user_app/filt tem p/t mp/umount ramdisk.imagegzip ramdisk.imagecp ram disk.image.gz ../linux-2.6-xlnx/arch/powerpc/boot/cd ../linux-2.6-xlnxmake ARCH=powerpc cleanmake ARCH=powerpc zImagecp arch/powerpc/boot/sim pleImage.initrd.virtex440-ml507.elf ../win_share_5/ComplexFIR_XOSL_PPC440This will take a few minutes to finish execution. As a result, an ELF file “simpleImage.initrd.virtex440-ml507.elf” will be copied to theComplexFIR_XOSL_PPC440 project directory.Downloading and ExecutionNow, the bitstream and the ELF file are ready, and we can download them to the FPGA, and run Linux.∙Connect the ML507 board with Xilinx USB Platform Cable via JTAG, and also connect the RS-232 serial cable and power adaptor. Turn on thepower switch.∙Open the Tera Term appli cation, select type “Serial”, and make sure the settings are 9600-8-N-1.∙In Xilinx XPS, Device Configuration → Download Bitstream. This will program the Virtex-5 FPGA via JTAG connection.∙Debug → Lauch XMD. For the first time open XMD, the XMD Debug Options Dialogue will appear. Just click OK to accept the default settings.∙Download the generated ELF file to FPGA and let it run as shown below.Watch the Linux boot display in the Tera Term window:The user application executable file “filt” is located in /tmp folder in the file system.Execute the user application. As a result, the APU accelerated with Impulse hardware runs 4.82 times faster than the software only version.This is the end of the tutorial.References1.Xilinx Open Source Linux Wiki: Configuring, Building andLoading Linux After 9/1/08/configuring-building-and-loading-linux-after-9-1-082.PowerPC Processor Reference Guide/support/documentation/user_guides/ug011.pdf3.PowerPC 405 Processor Block Reference Guide/support/documentation/user_guides/ug018.pdf4.Embedded Processor Block in Virtex-5 FPGAs Reference Guide/support/documentation/user_guides/ug200.pdf5.Accelerated System Performance with the APU Controller andXtremeDSP Slices/support/documentation/application_notes/xapp717.pdf6.GNU Compiler Collection (GCC): Assembler Instructions with CExpression Operands /onlinedocs/gcc-3.4.3/gcc/Extended-Asm.html7.AltiVec Instruction Cross-Reference/hardwaredrivers/ve/instruction_crossref.html8.Impulse Support Forum: APU and Linux http://impulse-/forums/index.php?showtopic=143&st=0&p=671。

UOJ⾮传统题配置⼿册⾃从我校使⽤ UOJ 社区版作为校内 OJ 之后，配置⾮传统题的旅程就从未停歇（然⽽是时候停下了（雾传统题的配置在⾥已经很详细了。

如果不会配置传统题，建议先去看 vfk 的⽂档。

提交答案样题：SZOJ2376 easy这好像是之前的⼀道模拟赛题。

UOJ 的内置 judger 有⼀个 feature (?)，就是在⽐赛的时候，提交答案题会测试所有的测试点并给你看评测结果，但只会告诉你每个测试点你是否拿到了分。

如果你拿到了分就会给你显⽰满分。

于是这题分数赛时最低的我终测之后最⾼（雾直接来看 problem.conf：submit_answer onn_tests 8input_pre easyinput_suf inoutput_pre easyoutput_suf outoutput_limit 64use_builtin_judger onpoint_score_1 8point_score_2 16point_score_3 16point_score_4 16point_score_5 16point_score_6 11point_score_7 11point_score_8 6写上 submit_answer on 表⽰这是提答题，其他的都跟传统题⼀样。

好像提交⽂件配置在配置数据的时候就会改掉反正我们 OJ 是这样的，所以不需要管。

函数式交互样题：SZOJ2506这事之前 pb 出的⼀道交互题，然后丢给我造的数据。

仍然是只看 problem.conf：n_tests 34n_ex_tests 3n_sample_tests 3input_pre datainput_suf inoutput_pre dataoutput_suf outtime_limit 1memory_limit 128output_limit 64n_subtasks 5// ...with_implementer ontoken dff2ece271eb429fuse_builtin_judger onuse_builtin_checker wcmp写上 with_implementer on 表⽰源代码与 implementer.cpp ⼀起编译。

Linux下‎的段错误（Segmen‎t ation‎fault）产生的原因及‎调试方法（经典）2009-04-05 11:25简而言之,产生段错误就‎是访问了错误‎的内存段，一般是你没有‎权限，或者根本就不‎存在对应的物‎理内存,尤其常见的是‎访问0地址.一般来说,段错误就是指‎访问的内存超‎出了系统所给‎这个程序的内‎存空间，通常这个值是‎由gdtr来‎保存的，他是一个48‎位的寄存器，其中的32位‎是保存由它指‎向的gdt表‎，后13位保存‎相应于gdt‎的下标，最后3位包括‎了程序是否在‎内存中以及程‎序的在cpu‎中的运行级别‎,指向的gdt‎是由以64位‎为一个单位的‎表，在这张表中就‎保存着程序运‎行的代码段以‎及数据段的起‎始地址以及与‎此相应的段限‎和页面交换还‎有程序运行级‎别还有内存粒‎度等等的信息‎。

一旦一个程序‎发生了越界访问，cpu就会产‎生相应的异常‎保护，于是segm‎e ntati‎o n fault就‎出现了.在编程中以下‎几类做法容易‎导致段错误,基本是是错误‎地使用指针引‎起的1)访问系统数据‎区，尤其是往系统保护的内‎存地址写数据‎最常见就是给‎一个指针以0‎地址2)内存越界(数组越界，变量类型不一‎致等) 访问到不属于‎你的内存区域‎解决方法我们在用C/C++语言写程序的‎时侯，内存管理的绝‎大部分工作都‎是需要我们来‎做的。

实际上，内存管理是一‎个比较繁琐的‎工作，无论你多高明‎，经验多丰富，难免会在此处犯‎些小错误，而通常这些错‎误又是那么的‎浅显而易于消‎除。

但是手工“除虫”（debug），往往是效率低‎下且让人厌烦‎的，本文将就"段错误"这个内存访问越界‎的错误谈谈如‎何快速定位这‎些"段错误"的语句。

下面将就以下‎的一个存在段‎错误的程序介‎绍几种调试方‎法：1 dummy_‎f uncti‎o n (void)2 {3 unsign‎e d char *ptr = 0x00;4 *ptr = 0x00;5 }67 int main (void)8 {9 dummy_‎f uncti‎o n ();1011 return‎0;12 }作为一个熟练‎的C/C++程序员，以上代码的b‎u g应该是很‎清楚的，因为它尝试操‎作地址为0的‎内存区域，而这个内存区‎域通常是不可‎访问的禁区，当然就会出错‎了。

linux调度原理进程调度依据调度程序运行时，要在所有可运行状态的进程中选择最值得运行的进程投入运行。

选择进程的依据是什么呢？在每个进程的task_struct结构中有以下四项：policy、priority、counter、rt_priority。

这四项是选择进程的依据。

其中，policy是进程的调度策略，用来区分实时进程和普通进程，实时进程优先于普通进程运行；priority是进程(包括实时和普通)的静态优先级；counter是进程剩余的时间片，它的起始值就是priority的值；由于counter在后面计算一个处于可运行状态的进程值得运行的程度goodness时起重要作用，因此，counter也可以看作是进程的动态优先级。

rt_priority是实时进程特有的，用于实时进程间的选择。

Linux用函数goodness()来衡量一个处于可运行状态的进程值得运行的程度。

该函数综合了以上提到的四项，还结合了一些其他的因素，给每个处于可运行状态的进程赋予一个权值(weight)，调度程序以这个权值作为选择进程的唯一依据。

关于goodness()的情况在后面将会详细分析。

进程调度策略调度程序运行时,要在所有处于可运行状态的进程之中选择最值得运行的进程投入运行。

选择进程的依据是什么呢?在每个进程的task_struct 结构中有这么四项：policy, priority , counter, rt_priority这四项就是调度程序选择进程的依据.其中,policy是进程的调度策略,用来区分两种进程-实时和普通；priority是进程(实时和普通)的优先级；counter 是进程剩余的时间片,它的大小完全由priority决定;rt_priority是实时优先级,这是实时进程所特有的，用于实时进程间的选择。

首先，Linux 根据policy从整体上区分实时进程和普通进程，因为实时进程和普通进程度调度是不同的，它们两者之间，实时进程应该先于普通进程而运行，然后，对于同一类型的不同进程，采用不同的标准来选择进程：对于普通进程，Linux采用动态优先调度，选择进程的依据就是进程counter的大小。

chatglm p-tunning原理
PT-Tuning是一种模型优化技术，用于将模型的预训练权重（Pretrained weights）微调到特定任务的优化权重（Fine-tuned weights）。

它的原理可以简单概括如下：
1. 预训练（Pretraining）：在大规模无标签数据上训练一个通用模型，如BERT，用于学习语言的各种特征。

2. 特定任务数据准备：将预训练模型应用于特定任务之前，需要准备特定任务的有标签数据。

这些数据包括输入样本和对应的标签。

3. 微调（Fine-tuning）：通过将特定任务的数据输入预训练模型，更新模型参数使其适应特定任务。

通常采用反向传播（Backpropagation）和梯度下降法（Gradient Descent）等优化算法来实现。

4. 学习率调度：微调过程中，由于预训练模型的权重已经进行了大规模训练，因此往往需要较小的学习率来微调模型，以避免损毁已经学到的知识。

学习率调度技术可用于动态地调整微调过程的学习率，以提高收敛速度和优化性能。

5. 模型评估和调优：微调模型后，需要评估其性能，并可根据评估结果进一步调整模型参数。

总体而言，PT-Tuning利用预训练模型在大规模无标签数据上
学习到的通用知识，通过微调模型使其适应特定任务，从而提高该任务的性能。

Linux网络包从中断到接收的一生内容来自SJTU,IPADS OS-16-Networklinux既然要讲，那就把一个包的整个包生都说了算了触发中断•在非虚拟化环境下，网卡通过DMA将packet写入内核的rx_ring环形队列缓冲区，并触发中断。

•如果在虚拟化环境下，VMM配置GIC ITS (Interrupt Translation Service) ，建立物理中断与虚拟中断的映射完成中断虚拟化使得网卡能直接向VM发出中断，同时通过IO虚拟化，网卡通过IOMMU将packet直接写入虚拟机内核的rx_ringTop Half•CPU在收到中断之后，调用网卡ISR也就是所谓的中断handler •分配sk_buf并入input_pkt_queue（如果队列已满则丢弃）•发出一个软中断NET_RX_SOFTIRQ，软中断可以被调度例如通过taskletBottom Half•sk_buf从input_pkt_queue传入process_queue，根据协议类型调用网络层协议的handler•ip_rcv执行包头检查，ip_router_input()进行路由，决定本机/转发/丢弃•tcp_v4_rcv执行包头检查，tcp_v4_lookup查询对应的socket 和connection，如果正常，tcp_prequeue将skb放进socket接收队列•socket随即唤醒所在的进程kqueue因为epoll没有论文，就说说kqueue是怎么做的吧，kqueue会根据socket绑定的knote链表（每个监听的kqueue都可能创建一个knote），将knote通过反向指针获得kqueue，将knote加入kqueue的就绪队列末尾。

如果此时恰好有进程正在监听的话，将会唤醒进程，kqueue会被扫描，并从就绪队列处获得所有的event，从而了解已经就绪的所有socket。

•唤醒的进程调用socket recv系统调用，如果是TCP则调用tcp_recvmsg从sk_buffer拷贝数据Batchnetif_receive_skb_list()Linux的NAPI还会继续延迟软中断的处理，等待其积累足够的skb后进行轮询，一次性处理所有的skb。

gdbstub 原理
gdbstub是一个调试器协议的实现，它允许开发人员在调试过程中与目标系统进行通信。

其基本原理如下：
启动目标系统：在启动目标系统时，gdbstub被嵌入到目标系统中。

这通常通过在编译目标系统时链接gdbstub库来完成。

调试协议通信：gdbstub与调试器（例如GDB）之间通过一个定义好的协议进行通信。

这个协议规定了如何发送和接收命令、数据和状态信息。

控制目标系统：通过发送调试命令，调试器可以控制目标系统的执行流程。

例如，它可以设置断点、单步执行代码、查看寄存器值等。

获取目标系统状态：gdbstub会捕获目标系统的状态信息，例如寄存器值、内存内容、堆栈信息等，并将这些信息发送给调试器。

断点和异常处理：当目标系统遇到断点或发生异常时，gdbstub会捕获这个事件，并将相关信息发送给调试器。

这使得开发人员能够在程序出错时获取有用的调试信息。

总的来说，gdbstub的作用就是在目标系统上运行，与调试器进行通信，并根据调试器的命令控制目标系统的执行，同
时将目标系统的状态信息发送给调试器。

这使得开发人员能够方便地对嵌入式系统进行调试和故障排除。