RELEASED
PM7366 FREEDM-8
DATA SHEET
PMC-1970930
ISSUE 4
FRAME ENGINE AND DATA LINK MANAGER
BSAD[27:0]:
The Base Address (BSAD[27:0]) bits defines the size and location of the memory space
required for the CBI registers. The BSAD[27:0] bits correspond to the most significant 28 bits
of the PCI address space.
The size of the address space required can be determined by writing all ones to Base Address
register and then reading from it. By scanning the returned value from the least significant bit
upwards, the size of the required address space can be determined. The binary weighted value of
the first one bit found (after the configuration bits) indicates the required amount of space. The
BSAD[7:0] bits are forced low to indicate that the CBI registers require 4K bytes of memory space.
After determining the memory requirements of the CBI registers, the PCI Host can map them to
its desired location by modifying the BSAD[27:8] bits in the Base Address register.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
224
PMC [ PMC-SIERRA, INC ]
