Register Description

Register Description

12

 

 

This chapter describes the registers of the Intel® 41210 Serial to Parallel PCI Bridge.

12.1Register Nomenclature and Access Attributes

 

Table 32 describes the nomenclature used for describing bit attributes throughout this chapter.

Table 32.

Bit Attribute Definitions

 

 

 

 

Mnemonic

Attribute

 

 

 

 

RO

Read-Only:This bit cannot be altered by software. This bit can be hard-wired to return a

 

fixed value at all times, or it can be set by hardware on an event.

 

 

 

 

 

 

 

Reserved and Preserved: These bits are reserved for future RW implementations; software

 

RsvdP

must preserve the value read for writes to bits. The Intel® 41210 Serial to Parallel PCI Bridge

 

 

hardware implements these bits as read-only 0s.

 

 

 

 

RsvdZ

Reserved and Zero: These bits are reserved for future RWC implementations; software must

 

use 0 for writes to bits. The 41210 hardware implements these bits as read-only 0s.

 

 

 

 

 

 

ROS

Read-Only Sticky: These bits are read-only and cannot be altered by software. The bits are

 

not cleared by reset and can be reset only with the PERST# reset condition.

 

 

 

 

 

 

RZSet

Read Zero to Set: Reading this bit when the current value of the bit is 0 causes the bit to flip

 

to a 1. Software must write a 1 to clear this bit. Writing a 0 has no effect.

 

 

 

 

 

 

RW

Read-Write:Software can do a full read and write of this bit.

 

 

 

 

RW1Set

Read and Write One to Set: Software must write a 1 to set this bit. Writing a 0 has no effect

 

on this bit. Software can clear this bit through a separate RWC bit, or it can be reset by

 

 

hardware.

 

 

 

 

RWS

Read-Write and Sticky: Software can read and write this bit. The bit can be reset only by a

 

PERST# reset.

 

 

 

 

 

 

RWC

Read and Write One to Clear: When this bit is set, software must write a 1 to this bit to clear

 

it. Writing a 0 has no effect.

 

 

 

 

 

 

 

Read and Write One to Clear and Sticky through reset: When this bit is set, software must

 

RWCS

write a 1 to this bit to clear it. Writing a 0 has no effect. The bit can be reset only by a PERST#

 

 

reset.

 

 

 

 

Strap

Strap: This is a read-only register. The power-on default is based on sampling a strap pin at

 

the rising edge of PERST#.

 

 

 

 

 

 

WT

Write Transient: This bit is always read as a 0. Writing a 1 to this bit causes other side-

 

effects that are specific to every WT bit.

 

 

 

 

 

Note: Software must not attempt to write to the registers that are marked “reserved”. Writing to these

 

registers yields undetermined results. Reads of these registers can yield either value. Note that the

 

behavior of individual register bits that are marked “reserved” is in accordance with the attribute

 

definition for that bit.

Intel® 41210 Serial to Parallel PCI Bridge Developer’s Manual

73

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Intel 41210 Register Description, Register Nomenclature and Access Attributes, Bit Attribute Definitions, PERST# reset