Motorola PPC/PMC-8260/DS1, Справочное руководство, Страница: 71 / 150

Firmware Power-Up Sequence
PPC/PMC-8260/DS1 4 - 7
Check for ROM image? The firmware can be configured to check for a ROM
image in the boot flash device or to start the primary
booter. This is done by setting the ROMSKIP bit in the
PCR register (see Table 12 “PCR Register Settings” page
4-13).
ROM image present? The firmware checks whether a ROM image is present at
address FE040108
16
.
Preset SYPCR register (option-
ally) At power up, the watchdog and the bus monitor are
enabled. You can configure your ROM image to make the
firmware change the System Protection Control register
(SYPCR) settings and to disable the watchdog and the
bus monitor. This is done by programming the ROM
image accordingly. For further information, see section
“SYPCR Register” on page 4-9.
Set power-up status (PSR) to
ROMEX Before the ROM image is executed, the value 3 is written
into the PSR. This information can be used to poll the
power-up status.
Set power-up status (PSR) to
RDY Before the primary booter is started, the value 2 is written
into the PSR. This status bit can be used to poll the
power-up status.
Table 10: Steps Performed During Power-Up
Step Description