Intel
®
81341 and 81342—Exception Initiator and Boot Sequence
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
734
Order Number: 315037-002US
10.3.2.3 Boot Sequence — coreID0 runs from Flash Memory and coreID1 runs
from SRAM Memory
1. Pull the external strap HOLD_X1_IN_RST# low to hold coreID1 in reset, while
pulling the external strap HOLD_X0_IN_RST# high to allow coreID0 to run.
2. coreID0 will start running after reset from Flash Memory.
3. coreID0 would scrub the SRAM memory, and download code image for coreID1 into
SRAM memory.
4. coreID0 will setup the SRAM Base Address Registers to 0 0000 0000H. This would
allow the core access to be claimed by the SRAM MCU during boot.
5. coreID0 would then clear the HOLD_X1_IN_RST# bit to release coreID1 from reset.
6. coreID1 would start running from SRAM Memory address.
Note:
The north interface of the internal bus bridge performs subtractive decoding. Normally
Flash (address starting at 0 0000 0000H) access by the core would be claimed by the
bridge north interface and forwarded to the south internal, where the Flash device is
located. The SRAM Memory Controller resides on the North internal bus. If the SRAM
Base Address Registers are setup to 0 0000 0000H by the Host processor via the Host
Interface, the core can then boot from the SRAM Memory.