IBM H SERIES RS/6000 User Manual

Also see for H SERIES RS/6000: Installation and service guide Installation and service guide

Adapter Power-On Self-Tests (POSTs)Two power-on self-tests (POSTs) are resident in the SSA adapter. The tests arePOST-1 and POST-2.POST-1 tests all the functions that are necessary to enable the adapter to communi-cate with the Micro Channel. POST-1 can fail for either of two reasons: A hardware error has been detected. In such instances, the POST code entersa tight loop, and does not put the identification of the SSA adapter into the pro-grammable option select (POS) registers. If this error occurs, the SSA adaptermust be exchanged for a new one. The flash erasable programmable read-only memory (EPROM) has a check sumthat is not valid. This error can be caused if the power fails while microcode isbeing downloaded. In such instances, the POST checks all the hardware that isneeded to download the microcode. If all the hardware is correct, the POST setsthe ROS level to zero, puts the identification of the SSA adapter into POS 0-1,and puts error data into the adapter status register.To recover from this type of error, microcode must be downloaded to the SSAadapter. If the using system can have an initial program load (IPL) without theadapter, the configuration code detects the down-level ROS code and downloadsthe latest level of code. The configuration code then uses control register bit 7 toreset the adapter and restart POST-1.If no error is detected during POST-1, the identification of the SSA adapter is put intothe POS registers, and POST-2 is started.POST-2 tests the remaining hardware on the SSA adapter card and tests the otherFRUs that are attached to the adapter. If this test fails, an error code is saved andsent to the using-system error log when the error logger becomes available. Aninternal health check continues to send the error code at regular intervals.10-2 RS/6000 Enterprise Server Model H Series User's Guide