HT82K28A データシートの表示（PDF） - Holtek Semiconductor

部品番号

コンポーネント説明

メーカー

HT82K28A

Win98 Keyboard Encoder

Holtek Semiconductor 

HT82K28A

Keys

· For code set 1, 2

All keys except the PAUSE key have a make and

break code. The PAUSE key has a make code only.

The defaults except for PAUSE are make/break/

typematic. In mode 1, 2 and 3 the key type may be

changed to be one of the following:

m ode1

m ode2

m ode3

¨ Typematic

¨ Make/break

¨ Make

¨ Typematic/make/break

All keys except PAUSE are typematic. Typematic

means that the KB keeps sending make codes if the

key is held down.

The data report is according to the typematic

rate/delay:

Default values are: delay 500ms ± 20%

10.9 char/sec ± 20%

The typematic rate and delay can be modified with

the F3 command.

¨ If two or more keys are held down, only the last key

pressed repeats at the typematic rate.

Typematic operation stops when the last key

pressed is released even if other keys are still held

down.

If a key is pressed and held down while keyboard

transmission is inhibited, only the first make code is

stored in the buffer overflow as a result of typematic

action.

Four key types are supported as shown:

Key type

press hold release

Typematic

Make/break

Make

Typematic/

make/break

make1

make1

make1

make1

make2

X

X

make2

X

break

X

break

Note:

²make1² send out only one make code.

²Make2² continue sending out make codes

until key is released.

²X² nothing sent out.

· For code set 3

¨ Typematic

¨ Make/break

¨ Make

¨ Typematic/make/break

Can be configured by command

Time interval between phantoms

The time interval between two continuous error codes

00/FF sent while phantom detected= 1000ms ± 20%

The keyboard should respond within 20ms, except

when performing the BAT or executing a reset com-

mand.

System command table

Command

FF - reSset

FE - resend

FD - set key type make

FC - set key type make/break

FB - set key type typematic

FA - set all keys typematic/make/break

F9 - set all keys make

F8 - set all keys make/break

F7 - set all keys typematic

F6 - set default

F5 - default disabled

F4 - enable

F3 - set typematic rate/delay

F2 - Read ID

F1 -

F0 - select alternate scan codes

EF -

EE - Echo

ED - set/reset status indicators

mode 1

y

y

y

y

y

y

y

y

y

y

y

y

y

y

x

y

x

y

y

mode 2

y

y

y

y

y

y

y

y

y

y

y

y

y

y

x

y

x

y

y

mode 3

y

y

y

y

y

y

y

y

y

y

y

y

y

y

x

y

x

y

y

Rev. 1.30

4

June 27, 2002

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