VT82C586B Просмотр технического описания (PDF) - Unspecified

Номер в каталоге

Компоненты Описание

производитель

VT82C586B

PCI Integrated Peripheral Controller

Unspecified 

9,$7HFKQRORJLHV,QF

VT82C586B

Port 64 - Keyboard / Mouse Command.......................... WO

This port is used to send commands to the keyboard / mouse

controller. The command codes recognized by the

VT82C586B are listed n the table below.

Note: The VT82C586B Keyboard Controller is compatible

with the VIA VT82C42 Industry-Standard Keyboard

Controller except that due to its integrated nature, many of the

input and output port pins are not available externally for use

as general purpose I/O pins (even though P13-P16 are set on

power-up as strapping options). In other words, many of the

commands below are provided and “work”, but otherwise

perform no useful function (e.g., commands that set P12-P17

high or low). Also note that setting P10-11, P22-23, P26-27,

and T0-1 high or low directly serves no useful purpose, since

these bits are used to implement the keyboard and mouse ports

and are directly controlled by keyboard controller logic.

Table 4. Keyboard Controller Command Codes

Code

20h

60h

Keyboard Command Code Description

Read Control Byte (next byte is Control Byte)

Write Control Byte (next byte is Control Byte)

9xh

Write low nibble (bits 0-3) to P10-P13

A1h Output Keyboard Controller Version #

A4h Test if Password is installed

(always returns F1h to indicate not installed)

A7h Disable Mouse Interface

A8h Enable Mouse Interface

A9h Mouse Interface Test (puts test results in port 60h)

(value: 0=OK, 1=clk stuck low, 2=clk stuck high,

3=data stuck lo, 4=data stuck hi, FF=general error)

AAh KBC self test (returns 55h if OK, FCh if not)

ABh Keyboard Interface Test (see A9h Mouse Test)

ADh Disable Keyboard Interface

AEh Enable Keyboard Interface

AFh Return Version #

B0h Set P10 low

B1h Set P11 low

B2h Set P12 low

B3h Set P13 low

B4h Set P22 low

B5h Set P23 low

B6h Set P14 low

B7h Set P15 low

B8h Set P10 high

B9h Set P11 high

BAh Set P12 high

BBh Set P13 high

BCh Set P22 high

BDh Set P23 high

BEh Set P14 high

BFh Set P15 high

Code

C0h

C1h

C2h

Keyboard Command Code Description

Read input port (read P10-17 input data to

the output buffer)

Poll input port low (read input data on P11-13

repeatably & put in bits 5-7 of status

Poll input port high (same except P15-17)

C8h Unblock P22-23 (use before D1 to change

active mode)

C9h Reblock P22-23 (protection mechanism for D1)

CAh Read mode (output KBC mode info to port 60

output buffer (bit-0=0 if ISA, 1 if PS/2)

D0h Read Output Port (copy P10-17 output port values

to port 60)

D1h Write Output Port (data byte following is written to

keyboard output port as if it came from keyboard)

D2h Write Keyboard Output Buffer & clear status bit-5

(write following byte to keyboard)

D3h Write Mouse Output Buffer & set status bit-5 (write

following byte to mouse; put value in mouse input

buffer so it appears to have come from the mouse)

D4h Write Mouse (write following byte to mouse)

E0h

Read test inputs (T0-1 read to bits 0-1 of resp byte)

Exh

Set P23-P21 per command bits 3-1

Fxh

Pulse P23-P20 low for 6usec per command bits 3-0

All other codes not listed are undefined.

Revision 1.0 May 13, 1997

-23-

Register Descriptions

Share Link: