![](http://datasheet.mmic.net.cn/330000/PM7366_datasheet_16444405/PM7366_229.png)
RELEASED
DATA SHEET
PM7366 FREEDM-8
ISSUE 4
PMC-1970930
FRAME ENGINE AND DATA LINK MANAGER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
216
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-8 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-8
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-8 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.