12. Register Descriptions
266
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.12
PCI-1 Vital Product Data Capability Register
PowerSpan II only supports VPD access from the Primary PCI Interface. The Secondary PCI Interface
reads zero for VPD accesses. VPD writes have no effect.
VPD can also be disabled when the NXT_PTR bit in the
“PCI-1 Compact PCI Hot Swap Control and
register is 0.
Register Name: P1_VPDC
Register Offset: 0E8
PCI
Bits
Function
PB
Bits
31-24
F
Reserved
0-7
23-16
VPDA
8-15
15-08
NXT_PTR
16-23
07-00
CAP_ID
24-31
Name
Type
Reset
By
Reset
State
Function
F
R/W
P1_RST
0
Data Transfer Complete Flag
Indicates when the transfer between the VPD Data register
and the EEPROM is complete. Software clears the bit to
initiate a read and PowerSpan II sets the bit when the read
data is available in the VPD Data register. Software sets the
bit to initiate a write and PowerSpan II clears the bit to
indicate when the data has been transferred.
VPDA [7:0]
R/W
P1_RST
0x00
Vital Product Data Address
The 8-bit address specifies the VPD address offset for the
VPD-Read or VPD-Write to the serial EEPROM. When I2C
chip select 0 is used for the VPD EEPROM the VPD address
translates a maximum of 64 bytes and 192 bytes are
available for VPD. The first 64 bytes of VPD is VPD-Read
Only, and the remaining 128 bytes — 192 bytes if separate
256 byte EEPROM used for VPD — is VPD-Read/Write.
NXT_PTR [7:0]
R
P1_RST
0x00
Next Pointer
VPD is the last Extended Capabilities Pointer
CAP_ID [7:0]
R
P1_RST
0x03
Capability ID