Revision 1.1
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G
SuperI/O Module
(Continued)
4.4.1
Table 4-4 lists the SIO Control and Configuration registers and Table 4-5 provides their bit formats.
SIO Control and Configuration Registers
Table 4-4. SIO Control and Configuration Register Map
Index
Type
Name
Power Rail
Reset Value
20h
RO
SID.
SIO ID
V
CORE
F5h
21h
R/W
SIOCF1.
SIO Configuration 1
V
CORE
01h
22h
R/W
SIOCF2.
SIO Configuration 2
V
PP
02h
27h
RO
SRID.
SIO Revision ID
V
CORE
01h
2Eh
---
RSVD.
Reserved exclusively for National use.
---
---
Table 4-5. SIO Control and Configuration Registers
Bit
Description
Index 20h
SIO ID Register - SID (RO)
Reset Value: F5h
7:0
Chip ID.
Contains the identity number of the module. The SIO module is identified by the value F5h.
Index 21h
SIO Configuration 1 Register - SIOCF1 (RW)
Reset Value: 01h
7:6
General Purpose Scratch.
When bit 5 is set to 1, these bits are RO. After reset, these bits can be R/W. Once changed to
RO, the bits can be changed back to R/W only by a hardware reset.
Lock Scratch.
This bit controls bits 7 and 6 of this register. Once this bit is set to 1 by software, it can be cleared to 0 only
by a hardware reset.
0: Bits 7 and 6 of this register are R/W bits. (Default)
1: Bits 7 and 6 of this register are RO bits.
Reserved.
SW Reset
. Read always returns 0.
0: Ignored. (Default)
1: Resets all devices that are reset by MR (with the exception of the lock bits) and the registers of the SWC.
Global Device Enable.
This bit controls the function enable of all the logical devices in the SIO module, except the SWC
and the RTC. It allows them to be disabled simultaneously by writing to a single bit.
0: All logical devices in the SIO module are disabled, except the SWC and the RTC.
1: Each logical device is enabled according to its Activate register at Index 30h. (Default)
5
4:2
1
0
Index 22h
Note:
SIO Configuration 2 Register - SIOCF2 (R/W)
Reset Value: 02h
This register is reset only when V
PP
is first applied.
7
Reserved.
General Purpose Scratch.
Battery-backed.
Reserved.
Reserved.
Reserved. (RO)
6:4
3:2
1
0
Index 27h
SIO Revision ID Register - SRID (RO)
Reset Value: 01h
7:0
SIO Revision ID. (RO)
This RO register contains the identity number of the chip revision. SRID is incremented on each revi-
sion.