A bit description table is typically included that indicates bit field names, a detailed field description, and field access
tags. Table 4–2 describes the field access tags.
Table 4–2. Bit Field Access Tag Descriptions
ACCESS
TAG
NAME
MEANING
R
Read
Write
Set
Field may be read by software.
W
S
Field may be written by software to any value.
Field may be set by a write of 1. Writes of 0 have no effect.
Field may be cleared by a write of one. Writes of 0 have no effect.
C
Clear
U
Update Field may be autonomously updated by PCI2040.
4.1 Vendor ID Register
This 16-bit value is allocated by the PCI Special Interest Group (SIG) and identifies TI as the manufacturer of this
device. The vendor ID assigned to TI is 104Ch.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Type
Default
Vendor ID
R
0
R
0
R
0
R
1
R
0
R
0
R
0
R
0
R
0
R
1
R
0
R
0
R
1
R
1
R
0
R
0
Register:
Type:
Offset:
Default:
Vendor ID
Read-only
00h
104Ch
4.2 Device ID Register
This 16-bit value is allocated by the vendor and identifies the PCI device. The device ID for the PCI2250 is AC23h.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Type
Default
Device ID
R
1
R
0
R
1
R
0
R
1
R
1
R
0
R
0
R
0
R
0
R
1
R
0
R
0
R
0
R
1
R
1
Register:
Type:
Offset:
Default:
Device ID
Read-only
02h
AC23h
4–2
TI [ TEXAS INSTRUMENTS ]
