PM7384 FREEDM-84P672
DATA SHEET
PMC-1990445
ISSUE 5
FRAME ENGINE AND DATA LINK MANAGER 84P672
11
PCI CONFIGURATION REGISTER DESCRIPTION
PCI configuration registers are implemented by the PCI Interface. These
registers can only be accessed when the PCI Interface is a target and a
configuration cycle is in progress as indicated using the IDSEL input.
Notes on PCI Configuration Register Bits:
1. Writing values into unused register bits has no effect. However, to ensure
software compatibility with future, feature-enhanced versions of the product,
unused register bits must be written with logic zero. Reading back unused
bits can produce either a logic one or a logic zero; hence unused register bits
should be masked off by software when read.
2. Except where noted, all configuration bits that can be written into can also be
read back. This allows the processor controlling the FREEDM-84P672 to
determine the programming state of the block.
3. Writable PCI configuration register bits are cleared to logic zero upon reset
unless otherwise noted.
4. Writing into read-only PCI configuration register bit locations does not affect
FREEDM-84P672 operation unless otherwise noted.
5. Certain register bits are reserved. These bits are associated with megacell
functions that are unused in this application. To ensure that the FREEDM-
84P672 operates as intended, reserved register bits must only be written with
their default values. Similarly, writing to reserved registers should be
avoided.
11.1 PCI Configuration Registers
PCI configuration registers can only be accessed by the PCI host. For each
register description below, the hexadecimal register number indicates the PCI
offset.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
284
PMC [ PMC-SIERRA, INC ]
