PC87307VUL National Semiconductor, PC87307VUL Datasheet - Page 27

• Manufacturer Part Number: PC87307VUL
• Description: PC87307/PC97307 Plug and Play Compatible and PC97 Compliant SuperI/O
• Manufacturer: National Semiconductor

2.3.1
Tables 2-5 through 2-10 describe the standard Plug and Play registers. For more detailed information on these registers,
refer the “Plug and Play ISA Specification, Version 1.0a, May 5, 1994.” .
20h - 2Fh
Index
00h
01h
02h
03h
04h
005
06h
07h
Standard Plug and Play (PnP) Register Definitions
Set RD_DATA Port Writing to this location modifies the address of the port used for reading from the
Vendor Defined
Resource Data
Number (CSN)
Serial Isolation
Logical Device
Config Control
Card Select
Wake[CSN]
Card Level,
Number
Status
Name
TABLE 2-5. PnP Standard Control Registers
Plug and Play ISA cards. Data bits 7-0 are loaded into I/O read port address bits
9-2.
Reads from this register are ignored. Bits1 and 0 are fixed at the value 11.
Reading this register causes a Plug and Play card in the Isolation state to compare
one bit of the ID of the board. This register is read only.
This register is write-only. The values are not sticky, that is, hardware automatically
clears the bits and there is no need for software to do so.
Bit 0 - Reset
Bit 1 - Return to the Wait for Key state.
Bit 2 - Reset CSN to 0.
A write to this port causes all cards that have a CSN that matches the write data in
bits 7-0 to go from the Sleep state to either the Isolation state, if the write data for
this command is zero, or the Config state, if the write data is not zero. It also resets
the pointer to the byte-serial device.
This register is write-only.
This address holds the next byte of resource information. The Status register must
be polled until bit 0 of this register is set to 1 before this register can be read.
This register is read-only.
When bit 0 of this register is set to 1, the next data byte is available for reading
from the Resource Data register.
This register is read-only.
Writing to this port assigns a CSN to a card. The CSN is a value uniquely assigned
to each ISA card after the serial identification process so that each card may be
individually selected during a Wake[CSN] command.
This register is read/write.
This register selects the current logical device. All reads and writes of memory, I/O,
interrupt and DMA configuration information access the registers of the logical
device written here. In addition, the I/O Range Check and Activate commands
operate only on the selected logical device.
Vendor defined registers.
Writing this bit resets all logical devices and restores the contents of
configuration registers to their power-up (default) values.
In addition, all the logical devices of the card enter their default state and the
CSN is preserved.
Writing this bit puts all cards in the Wait for Key state, with all CSNs preserved
and logical devices not affected.
Writing this bit causes every card to reset its CSN to zero.
Configuration
27
Definition
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