
3.0 Device Architecture and Configuration
(Continued)
www.national.com
48
Revision1.2
P
3.6
The following abbreviations are used to indicate the Register Type:
REGISTER TYPE ABBREVIATIONS
G
R/W
= Read/Write.
G
R
= Read from a specific register (write to the same address is to a different register).
G
W
= Write (see above).
G
RO
= Read Only.
G
WO
= Write Only. Reading from the bit returns 0.
G
R/W1C= Read/Write 1 to Clear. Writing 1 to a bit clears it to 0. Writing 0 has no effect.
G
R/W1S = Read/Write 1 to Set. Writing 1 to a bit sets its value to 1. Writing 0 has no effect.
In the registers below, use one of the following methods to handle the
Reserved
bits:
G
Write 0 to reserved bits, unless another “required value” is specified. This method can be used for registers contain-
ing bits of all types.
G
Use read-modify-write to preserve the values of the reserved bits. This method can be used only for registers con-
taining bits of R/W, RO, R/W1C and R/W1S types.
3.7
This section describes the ServerI/O configuration and ID registers (those registers with first level indexes in the range of
20h - 2Eh). See Table 16 for a summary and directory of these registers.
SERVERI/O CONFIGURATION REGISTERS
Table 16. ServerI/O Configuration Registers
Index
Mnemonic
Register Name
Power Well
Type
Section
20h
SID
ServerI/O ID
V
SB
RO
3.7.1
21h
SIOCF1
ServerI/O Configuration 1
V
SB
Varies per bit
3.7.2
22h
SIOCF2
ServerI/O Configuration 2
V
SB
R/W or RO
3.7.3
23h
SIOCF3
ServerI/O Configuration 3
V
SB
R/W or RO
3.7.4
24h
SIOCF4
ServerI/O Configuration 4
V
SB
R/W or RO
3.7.5
25h
SIOCF5
ServerI/O Configuration 5
V
SB
R/W or RO
3.7.6
26h
SIOCF6
ServerI/O Configuration 6
V
SB
Varies per bit
3.7.7
27h
SRID
ServerI/O Revision ID
V
SB
RO
3.7.8
28h
SIOCF8
ServerI/O Configuration 8
V
SB
R/W
3.7.9
29h
CLOCKCF Clock Generator Configuration
V
SB
Varies per bit
3.7.10
2Ah
ACBCF
ACCESS.bus Configuration
V
PP
R/W or RO
3.7.11
2Bh - 2Fh Reserved for National use