Table 5-4. Sio Control And Configuration Register Map; Table 5-5. Sio Control And Configuration Registers - AMD Geode SC1200 Data Book

SuperI/O Module
5.4.1 SIO Control and Configuration Registers
Table 5-4 lists the SIO Control and Configuration registers and Table 5-5 provides their bit formats.
Index Type Name
20h RO SID. SIO ID
21h R/W SIOCF1. SIO Configuration 1
22h R/W SIOCF2. SIO Configuration 2
27h RO SRID. SIO Revision ID
2Eh --- RSVD. Reserved exclusively for AMD use.
Bit Description
Index 20h
7:0 Chip ID. Contains the identity number of the module. The SIO module is identified by the value F5h.
Index 21h
7:6 General Purpose Scratch. When bit 5 is set to 1, these bits are RO. After reset, these bits can be read or write. Once
changed to RO, the bits can be changed back to R/W only by a hardware reset.
5 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.
4:2 Reserved.
1 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.
0 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)
Index 22h
Note: This register is reset only when V
7 Reserved.
6:4 General Purpose Scratch. Battery-backed.
3:2 Reserved.
1 Reserved.
0 Reserved. (RO)
Index 27h
7:0 SIO Revision ID. (RO) This RO register contains the identity number of the chip revision. SRID is incremented on each revi-
sion.
AMD Geode™ SC1200/SC1201 Processor Data Book

Table 5-4. SIO Control and Configuration Register Map

Table 5-5. SIO Control and Configuration Registers

SIO ID Register - SID (RO)
SIO Configuration 1 Register - SIOCF1 (RW)
SIO Configuration 2 Register - SIOCF2 (R/W)
is first applied.
PP
SIO Revision ID Register - SRID (RO)
32579B
Power Rail Reset Value
V F5h
CORE
V 01h
CORE
V 02h
PP
V 01h
CORE
--- ---
Reset Value: F5h
Reset Value: 01h
Reset Value: 02h
Reset Value: 01h
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