Kontron AT8402 User Manual Manual de usuario descargar pdf (Pagina 71)

AT8402 Software Description

Page 4 - 7 AT8402 User Guide

4.3.1 Power on self Test

4.3.1.1 Test Routines

Upon power on or system reset, the bootloader performs a set of Power On Self Tests (POST)

to check the integrity of specific components. Components where a POST is available are:

• SDRAM

• PPC405 serial line

• PPC405 I2C

• PPC405 FE

In the case that a POST fails, a POST error code is written into the postcode high byte register

of the onboard CPLD. The boot process is not stopped as there are good chances the board

can boot even in case of POST errors. The postcode high byte register is also accessible by

the IPMC which can report error codes to a separate management instance. Thus more com-

prehensive diagnostic tests could be started.

The following table shows a list of available POST routines including POST error codes.

4.3.1.2 Boot Steps

In addition to the Power On Self Tests described above, the bootloader logs the board startup

sequence in the postcode low byte register. A postcode value is written each time a step in the

start sequence has been completed successfully. The postcode stored is also accessible by

the IPMC. In the case that an error occurs during execution of a step, the boot sequence is

stopped because a fatal error has occurred with great likelihood. In this case, a management

instance can read the last postcode written via the IPMC and thus determine where the fatal

error has occurred.

Table 4-1: POST routines and error codes

Device Test POST Error Code

SDRAM Data bus - walking 1 test PCW_DLINE

SDRAM Address bus - walking 1 test PCW_ALINE

SDRAM Memory - read/write test PCW_MEM

PPC405 UART Serial loopback teststring PCW_SERIAL

PPC405 I2C Bus scan for devices from I2C_ADDR_LIST PCW_I2C

PPC405 FE Phy access PCW_ETH1

PPC405 FE Phy loopback test using special Ethernet test frame PCW_ETH2

KCS KCS READY signal test KCSCTL

1 2 ... 66 67 68 69 70 71 72 73 74 75 76 ... 88 89

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Kontron AT8402 User Manual Manual de usuario Pagina 71