1 OCLA_Extension The Alpha EV7 On-Chip Logic Analyzer (OCLA) utility collects Program Counter (PC) traces in a portion of the Alpha EV7 cache. This data enables the user to tell which instructions each Alpha EV7 CPU on the system has executed. When entered by itself with no command keyword, the OCLA command lists the OCLA command options. SDA> OCLA You can get full help on OCLA by entering HELP OCLA at the SDA> prompt. NOTE When you use the ANALYZE/CRASH command to analyze a crash dump, the only OCLA commands you can use are OCLA SHOW STATUS and OCLA SHOW TRACE. 2 Overview OCLA enables the user to tell which instructions each Alpha EV7 CPU has executed by setting aside one seventh of the Alpha EV7 cache as acquisition memory which stores the virtual addresses of instructions executed by the Alpha EV7 CPU. The acquisition memory in the cache can later be analyzed with an SDA extension. The acquisition of instructions can be enabled or disabled while the system is running, thereby allowing the acquisition of instruction streams for a given period of time without the need to restart the system. If the OCLA is enabled and started, and your system subsequently fails due to a crash, the current acquisition memory is automatically saved to the system dump file. The instructions executed by each CPU prior to the system failure can then be analyzed with SDA. Upon restart of the system, the acquisition memory in the EV7 is still there and can be copied into system memory using the OCLA ENABLE and OCLA DUMP commands. If the STOP/CPU command is issued on a CPU for which OCLA has been enabled, OCLA is automatically disabled if the CPU is allowed to leave the active set. When a CPU is started with the START/CPU command, OCLA is not automatically enabled; rather, it must be enabled using SDA. 2 DISABLE Disables the OCLA and returns the cache set to the Alpha EV7 CPU. Format OCLA DISABLE [/CPU=n] 3 Qualifier /CPU /CPU=n Specifies the CPU on which OCLA should be disabled. If this qualifier is omitted, OCLA is disabled on every CPU in the system. 2 DUMP Copies the acquisition memory in the Alpha EV7 cache to a region in system space for later analysis by SDA. When a system fails, data collected in the EV7 cache is automatically saved in the system dump file for each enabled CPU. (See the OCLA SHOW TRACE command for more information.) Format OCLA DUMP [/CPU=n] 3 Qualifier /CPU /CPU=n Specifies the CPU for which to dump the acquisition memory. If this qualifier is omitted, the acquisition memory is dumped for all CPUs. 2 ENABLE Enables the OCLA. Reserves one-seventh of the EV7 cache as acquisition memory for instructions. Format OCLA ENABLE [/CPU=n] [/RESET] 3 Qualifiers /CPU /CPU=n Specifies the CPU on which to enable OCLA. If this qualifier is omitted, OCLA is enabled on every CPU in the system. /RESET Initializes the OCLA to default values. Under certain circumstances, the OCLA might not be initialized properly when the system is powered on. For more information, see the OCLA SHOW REGISTER command. If you wish to reset only certain registers to default values, use the OCLA SET REGISTER/RESET command. 2 HELP Provides online help on OCLA commands. Format OCLA HELP 2 LOAD Loads the OCLA$PCTRACE execlet. This must be done before enabling any OCLA. Format OCLA LOAD 2 SET 3 REGISTER Resets a specified OCLA register to its default value. The /RESET qualifier is required for this operation. Format OCLA SET REGISTER /RESET keyword 4 Parameter keyword Specifies which OCLA register to reset to its default value. The valid keywords are as follows: MISC OCLA 1 miscellaneous register OCLA1_CTL OCLA 1 control register PC_CTL OCLA 1 PC control register SMASK OCLA 1 select mask register SMATCH OCLA 1 select match register TMASK OCLA 1 trigger mask register TMATCH OCLA 1 trigger match register NOTE You cannot reset all registers using a single command if OCLA has already been enabled. You must first disable OCLA using the OCLA DISABLE command. You can then reset all the registers by performing an OCLA ENABLE/RESET command. 4 Qualifier /RESET This qualifier is required to reset the specified register to its default value. 2 SHOW 3 REGISTER Displays detailed information about OCLA registers. Format OCLA SHOW REGISTER [/CPU=n] 4 Qualifier /CPU /CPU=n Specifies the CPU for which to display registers. If this qualifier is omitted, registers are displayed for all CPUs. 3 STATUS Displays the status of an OCLA. Format OCLA SHOW STATUS [/CPU=n] 4 Qualifier /CPU /CPU=n Specifies the CPU for which to show OCLA status. If this qualifier is omitted, status is displayed for all CPUs. 3 TRACE Decodes the acquired compressed instruction stream and displays it. Format OCLA SHOW TRACE [/CPU=n] [/LAST=n][/NOPAL][/REVERSE][/SUMMARY][/SYMBOLIZE] 4 Qualifiers /CPU /CPU=n Specifies the CPU for which to show data. If this qualifier is omitted, trace data is displayed for all CPUs. /LAST /LAST=n Displays the last n instructions. If this qualifier is omitted, trace data is displayed for all instructions. /NOPAL Do not include PAL code when displaying instructions. /REVERSE Displays the instructions in reverse order. /SUMMARY Displays the last 42 instructions. /SYMBOLIZE Attempts to symbolize each instruction. 2 START Starts the acquisition of instructions into acquisition memory. Format OCLA START [/CPU=n] 3 Qualifier /CPU /CPU=n The CPU on which to start instruction acquisition. If this qualifier is omitted, instruction acquisition is started on all CPUs. 2 STOP Stops the acquisition of instructions. Format OCLA STOP [/CPU=n] 3 Qualifier /CPU /CPU=n Specifies the CPU on which to stop acquisition. If this qualifier is omitted, acquisition is stopped on all CPUs. 2 UNLOAD Unloads the OCLA$PCTRACE execlet and returns the acquisition buffers to the system. Format OCLA UNLOAD