HOLTEK HT82K629A User Manual

Windows 2000 USB+PS/2 Keyboard Encoder

Features

·

Operating voltage: 4.4V~5.5V

·

Operating frequency: f

·

Design for Windows 95/98/NT/2000/XP

·

Phantom key detection

·

Low voltage reset function

·

USB and PS2 modes supported

·

Auto detect USB or PS2 interface

·

USB 1.1 low speed function

General Description

The HT82K629A can function both in USB and PS2 in
terface environment. For PS2 interface, it supports IBM
PC/AT, IBM PS/2 and all compatible machines and pro
vides a 16-character first-in-first-out buffer in which data

Block Diagram

SYS

=6M

HT82K629A

·

Supports PS2 code set 1 and code set 2

·

Supports multimedia key

·

Supports ACPI key

·

Supports mini-keyboard with Fn key

·

Built-in Watchdog Timer

·

HALT function and wake-up feature for USB mode to
reduce power consumption

·

40-pin DIP package

is stored. For USB interface, it can support the USB

­standard request as well as HID class request version

1.1.

-

U S B D + / P S 2 C L K

U S B D - / P S 2 D A T A

V 3 3 O

O S C 1

O S C 2

V D D

V S S

U S B

T r a n s c e i v e r

U S B

R e c e i v e r

U S B

T r a n s m i t t e r

V o l t a g e

R e g u l a t o r

C l o c k

G e n e r a t o r

R C R e s e t

R e g i s t e r S e t

U S B S e r i a l

I n t e r f a c e E n g i n e ( S I E )

& C o n t r o l L o g i c

M a i n

S t a t e M a c h i n e

S u s p e n d

C o n t r o l

H o l t e k 8 - b i t

M i c r o c o n t r o l l e r

F I F O s

Rev. 1.40 1 September 15, 2004

HT82K629A

Pin Assignment

C 1 7

1

C 1 6

2

R 3

3

R 2

4

R 1

5

R 0

N U M

C A P S

C 1 2

C 1 3

C 1 4

C 1 5

V D D

V 3 3 O

C 0

C 1

6

7

8

9

1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

2 0

F n _ S e l

S C R O L L

U S B D + / C L K

U S B D - / D A T A

H T 8 2 K 6 2 9 A

4 0 D I P - A

Pin Description

Pin No. Pin Name I/O Description

1, 2, 11~14
19~26, 31~34
39, 40

3~6, 35~38 R0~R7 I Keyboard matrix scanning input pins

7 Fn_Sel I Mini-keyboard select, the function is enabled if connected to

8 NUM O Num lock indicator

9 CAPS O Caps lock indicator

10 SCROLL O Scroll lock indicator

15 VDD

16 V33O

17 USBD+/CLK I/O

18 USBD-/DATA I/O

27 VSS

28 RESET

29
30

C0~C19 O

OSCO
OSCI

Keyboard matrix scanning output pins

Positive power supply

¾

3.3V regulator output

¾

USBD- or PS2 CLK I/O line
USB or PS2 function is controlled by software control register.

USBD- or PS2 DATA I/O line
USB or PS2 function is controlled by software control register.

¾

Negative power supply, ground

I Schmitt trigger input. Active low.

OIOSCO, OSCI are connected to a 6MHz or 12MHz crystal/resonator for

the internal system clock.

C 1 8

4 0

C 1 9

3 9

R 4

3 8

R 5

3 7

R 6

3 6

R 7

3 5

C 1 1

3 4

C 1 0

3 3

C 9

3 2

C 8

3 1

O S C I

3 0

O S C O

2 9

R E S E T

2 8

V S S

2 7

C 7

2 6

C 6

2 5

C 5

2 4

C 4

2 3

C 3

2 2

C 2

2 1

VSS

.

Absolute Maximum Ratings

Supply Voltage ..........................VSS-0.3V to VSS+6.0V

Input Voltage .............................V

3V to VDD+0.3V

SS-0.

Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those
listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliabil
ity.

Rev. 1.40 2 September 15, 2004

Storage Temperature ...........................-50°Cto125°C

Operating Temperature ..............................0°Cto70°C

-

HT82K629A

D.C. Characteristics

Symbol Parameter

V

f

I

I

V

R

V

V

V

V

I

I

I

I

I

I

DD

SYS

SB

OP

V330

ph

IL1

IH1

IL2

IH2

OL1

OL2

OL3

OL4

OH1

OH2

Operating Voltage 5V

Operating Frequency 5V f

Standby Current 5V No load,systemHALT

Operating Current 5V

3.3V Regulator Output 5V

Internal Pull-high Resistance
(C0~C19, R0~R7)

Input Low Voltage for I/O Ports 5V

Input HighVoltageforI/OPorts 5V

Input Low Voltage (RESET)5V

Input High Voltage (RESET)5V

Sink Current (Fn_sel) 5V

Sink Current (R0~R7) 5V

Sink Current (C0~C19, NUM,
CAPS, SCROLL)

Sink Current (C0~C19, NUM,
CAPS, SCROLL)

Source Current (Fn_sel) 5V

Source Current (C0~C19,
R0~R7, NUM,CAPS, SCROLL)

Test Conditions

V

DD

SYS

No load, f

I

V33O

5V

V

OL

V

OL

V

5V

OL

V

5V

OL

V

OH

V

5V

OH

Ta=25°C

Conditions

¾

Min. Typ. Max. Unit

4.4

¾

5.5 V

=6MHz 5.9747 6 6.0258 MHz

500

mA

12 mA

kW

0.8 V

5V

0.4V

V

¾

¾

¾

¾

DD

DD

V

V

mA

mA

mA

mA

mA

mA

=-5mA

=0.4V

=0.4V

=0.4V

=3.4V

=3.4V

=3.4V

SYS

¾

¾

¾

¾

¾

=6MHz

¾¾

¾¾

3 3.3 3.6 V

25 50 75

0

2

0

0.9V

DD

¾

¾

¾

¾

10 25

510

24

12 17

-8 -16 ¾

-2 -5 ¾

A.C. Characteristics

Symbol Parameter

f

WDT

Built-in 32kHz RC OSC for Watchdog Timer

Test Conditions

V

DD

Conditions

Min. Typ. Max. Unit

¾¾¾32¾

Ta=25°C

kHz

Rev. 1.40 3 September 15, 2004

Functional Description

Command from the Host

The following table shows the commands that the host
may send and their hexadecimal values.

Command Hex Value

Set/Reset Status Indicators ED

Echo EE

Invalid Command EF

Select Alternate Scan Codes F0

Invalid Command F1

Read ID F2

Set Typematic Rate/Delay F3

Enable F4

Default Disable F5

Set Default F6

Set All Keys - Typematic

Set All Keys - Make/Break

Set All Keys - Make

Set All Keys - Typematic/Make/Break

Set Key Type - Typematic

Set Key Type - Make/Break

Set Key Type - Make

Resend FE

Reset FF

The commands may be sent to the HT82K629A at any
time and the HT82K629A will respond within 25ms ex­cept whenperforming the internal diagnostics or execut­ing a Reset command.

EDH - Set/Reset Status Indicators

Three status indicators on the keyboard-Num Lock,
Caps Lock, and Scroll Lock-are accessible by the host.
The HT82K629A activates or deactivates these indica
tors when it receives a valid command-code sequence
from the system. The command sequence begins with
the command byte (hex ED). The HT82K629A responds
to the command byte with ACK, discontinues scanning,
assignments for this option byte are as follow:

Bit Indicator

0 Scroll Lock Indicator

1 Num Lock Indicator

2 Caps Lock Indicator

3~7 Reserved (Must be 0)

If a bit for an indicator is set to 1, the indicator is turned
on. If a bit is set to 0, the indicator is turned off.

F7

F8

F9

FA

FB

FC

FD

HT82K629A

The HT82K629A responds to the option byte with ACK,
sets theindicatorsandif the HT82K629Awas previously
enabled, continues scanning. The status of the indica
tors will reflect the bits in the option byte and can be acti
vated or deactivated in any combination. If another
command is received in place of the option byte, execu
tion of the Set/Reset Mode Indicators command is
stopped, with no change to the indicator status, and the
new command is processed.

Immediately after power-on, the lights default to the off
state. If the Set Default and Default Disable commands
are received, the lamps remain in the state they were in
before the command was received.

EEH - Echo

Echo is a diagnostic aid. When the HT82K629A re
ceives this command, it issues a hex EE response and if
the HT82K629A was previously enabled, continues
scanning.

EFH and F1H - Invalid Command

EFH and F1H are invalid commands and are not sup
ported. If HT82K629A receives one of these and sends
it, the HT82K629A will not acknowledge the command,
but returns a Resend command and continues in its pre­vious scanning state.

F0H - Select Alternate Scan Codes

This commandinstructstheHT82K629Ato select one of
the two sets of scan codes. The HT82K629A acknowl­edges receipt of this command with ACK, clears both
the output buffer and the typematic key. The host then
sends the option byte and the keyboard responds with
another ACK. An option byte value of hex 01 selects
scan code set 1, hex 02 selects set 2.

An option byte value of hex 00 causes the HT82K629A
to acknowledge with ACK and sends a byte telling the
host which scan code set is currently in use.

-

After establishing the new scan code set, the
HT82K629A returns to the scanning state it was in be
fore receiving the Select Alternate Scan Codes com
mand.

F2H - Read ID

This command requests identification information from
the HT82K629A. The HT82K629A responds with
discontinues scanning and sends the two keyboard ID
bytes hex 83h and ABh. After the output of the second
ID byte, the HT82K629A resumes scanning.

ACK

-

-

-

-

-

-

-

,

Rev. 1.40 4 September 15, 2004

HT82K629A

F3H - Set Typematic Rate/Delay

The host issues the Set Typematic Rate/Delay com
mand to change the typematic rate and delay. The
HT82K629A responds to the command with ACK, stops
scanning and waits for the system to issue the rate/de
lay value byte. The HT82K629A responds to the value
byte with another ACK, sets the rate and delay to the
value indicated, and continues scanning (if it was previ
ously enabled). Bits 6 and 5 indicate the delay, and bits
4, 3, 2, 1 and 0 indicate the rate. Bit7 is always 0. The
delay is equal to 1 plus the binary value bit 6 and 5, mul
tiplied by 250ms±20%.

The period (interval from one typematic output to the
next) is determined by the following equation:

Period = (8+A)*(2^B)*0.00417 seconds.

Where:

A = binary value of bits 2, 1, and 0.

B = binary value of bits 4, and 3.

The typematic rate is 1 for each period and are listed as
follows:

Bit

00000 30.0 10000 7.5

00001 26.7 10001 6.7

00010 24.0 10010 6.0

00011 21.8 10011 5.5

00100 20.0 10100 5.0

00101 18.5 10101 4.6

00110 17.1 10110 4.3

00111 16.0 10111 4.0

01000 15.0 11000 3.7

01001 13.3 11001 3.3

01010 12.0 11010 3.0

01011 10.9 11011 2.7

01100 10.0 11100 2.5

01101 9.2 11101 2.3

01110 8.0 11110 2.1

01111 8.0 11111 2.0

The default values for the HT82K629A are as follows:

Typematic rate= 10.9 characters per second ± 20%

Delay = 500ms±20%

The execution of this command stops without changes
to the existing rate if another command is received in
stead of the rate/delay value byte.

Typematic

Rate ± 20%

Bit

Typematic

Rate ± 20%

F4H - Enable

Upon receipt of this command, the HT82K629A will re

­spond with ACK, clears its output buffer, clears the last

typematic key, and starts scanning.

-

F5H - Default Disable

The Default Disable command resets all conditions to
the power on default states. The HT82K629A will

­respond with
fault typematic rate/delay, and clears the last typematic
key. The HT82K629A then stops scanning and awaits

­further command.

F6H - Set Default

The Set Default command resets all conditions to the
power on default states. The HT82K629A will respond
with ACK, clears its output buffer, sets the default key
typematic rate/delay, and clears the last typematic key
then continues scanning.

F7H, F8H, F9H, FAH - Set All Keys

Since HT82K629A do not support keyboard code set 3
format, so it will not acknowledge the command but re
turns a Resend command and continues in its previous
scanning state.

FBH, FCH, FDH - Set Key Type

Since HT82K629A do not support keyboard code set 3
format, so it will not acknowledge the command but re­turns a Resend command and continues in its previous
scanning state.

FEH - Resend

The hostsendsthiscommand when it detects an error in
any transmissionfrom the HT82K629A. It is sent only af
ter a data transmission and before the host allows the
next data output. When a Resend is received, the
HT82K629A sends the previous output again (unless
the previous output was Resent, in which case the
HT82K629A sends the last byte before the Resend
command).

-

, clears its output buffer, sets the de

ACK

-

-

-

-

Rev. 1.40 5 September 15, 2004

HT82K629A

Commands to the Host

The following table shows the commands that the
HT82K629A may send to the host and their hexadeci

mal values.

Command Hex Value

Key Detection Error/Overrun 00 (Code Set 2)

Keyboard ID 83AB

Bat Completion Code AA

Bat Failure Core FC

Echo EE

Acknowledge FA

Resend FE

Key Detection Error/Overrun FF (Code Set 1)

00H or FFH - Key Detection Error

The HT82K629Asends a key detection error character if
conditions in the keyboard make it impossible to identify
a switch closure. If the HT82K629A is using scan code
set 1, the code is FFH. For sets 2, the code is 00H.

00H or FFH - Overrun

An overrun character is placed in the HT82K629A buffer
and replaces the last code when the buffer capacity has
been exceeded. The code is sent to the host when it
reaches the top of the buffer queue. If the HT82K629Ais
using scan code set 1, the code is

. For sets 2, the

FFH

code is 00H.

83AbH - Keyboard ID

The keyboard ID consists of 2 bytes, Hex 83AbH. The
HT82K629A responds to the Read ID with ACK, discon­tinues scanning and sends 2 ID bytes. The low byte is
sent first followed by the high byte. Following the output
of Keyboard ID, the HT82K629A begins scanning.

EEH - Echo

The HT82K629A sends this code in response to an
Echo command.

AAH - BAT Completion Code

Following a satisfactory completion of the BAT, the
HT82K629A sends AAH. Any other code indicates key
board failure.

FCH - BAT Failure Code

If a BAT failure occurs, the HT82K629A sends this code,
discontinues scanning and waits for a host response or
reset.

FEH - Resend

The HT82K629A issues a Resend command following
receipt of an invalid input or any input with incorrect par
ity. If the host sends nothing to the HT82K629A, no re
sponse is required.

Data Communications

·

Data output

-

¨

If CLK=0, no transmission (keyboard is inhibited).

¨

If CLK=1, DATA=0, no transmission (system re
quest to send).

¨

If CLK=1, DATA=1, transmission permitted.

¨

Data will be valid before the trailing edge and be
yond the leading edge of the clock.

¨

The KB checks the clock line for an active level ev
ery 60ms.

¨

If line contention occurs (system brings the clock
low before the tenth clock), set clock=data=high.

·

Data input

¨

The system overrides the clock line for at least
60ms.

¨

The keyboard checks the clock line state at inter
vals of 10ms.

¨

If a system request-to-send is detected, the key
board counts 11 data bits.

¨

Data will be valid before the rising edge and beyond
the falling edge.

¨

After the 10th bit, the keyboard checks for an active
level onthe ²data² line. If the line isactive it is forced
to be inactive, and counts one more bits.

Note: This action signals the system that the

keyboard has received its data. Upon

reception of thissignal, the system returns

to the ready state, in which it can accept
keyboard outputs or goes to the inhibit
state until it is ready.

If the keyboard ²data² line is found to be at an inactive
level followingthe 10th bit, a frame error has occurred,
and the keyboard continues to count until the ²data²
line becomes active. The keyboard then makes the
²data² line inactive and sends a Resend.

Data Stream

Mode 1,2,3

B1
B2
B3
B4
B5
B6

-

B7
B8
B9
B10
B11

Start bit (always 0)
Data bit 0
Data bit 1
Data bit 2
Data bit 3
Data bit 4
Data bit 5
Data bit 6
Data bit 7
Parity bit (odd par)
Stop bit (always 1)

Note: The parity bit is either 1or 0, and the 8 data bits,

plus the parity bit, always have an odd number
of 1ms.

-

-

-

-

-

-

-

Rev. 1.40 6 September 15, 2004

HT82K629A

Key Code Set 1

Key Number

and Symbol

1 ~ ' 29/A9 47 X 2D/AD

2 ! 1 02/82 48 C 2E/AE

3 @ 2 03/83 49 V 2F/AF

4 # 3 04/84 50 B 30/B0

5 $ 4 05/85 51 N 31/B1

6 % 5 06/86 52 M 32/B2

7 ^ 6 07/87 53 < , 33/B3

8 & 7 08/88 54 > . 34/B4

9 * 8 09/89 55 ? / 35/B5

10 ( 9 0A/8A 57 Shift (R) 36/B6

11 ) 0 0B/8B 58 Ctrl (L) 1D/9D

12 _ - 0C/8C 60 Alt (L) 38/B8

13 + = 0D/8D 61 Space 39/B9

14 Keycode14 (*J) 7D/FD 62 Alt (R) E0 38/E0 B8

15 Back Space 0E/8E 64 Ctrl (R) E0 1D/E0 9D

16 Tab 0F/8F 90 Num Lock 45/C5

17 Q 10/90 91 7 Home 47/C7

18 W 11/91 92 4

19 E 12/92 93 1 End 4F/CF

20 R 13/93 96 8

21 T 14/94 97 5 4C/CC

22 Y 15/95 98 2

23 U 16/96 99 0 Ins 52/D2

24 I 17/97 100 * 37/B7

25 O 18/98 101 9 PgUp 49/C9

26 P 19/99 102 6

27 { [ 1A/9A 103 3 PgDn 51/D1

28 } ] 1B/9B 104 . Del 53/D3

29 Keycode29 (*4) 2B/AB 105 - 4A/CA

30 Caps Lock 3A/BA 106 + 4E/CE

31 A 1E/9E 107 Keycode107 (*B) 7E/FE

32 S 1F/9F 108 Enter_R E0 1C/E0 9C

33 D 20/A0 110 ESC 01/81

34 F 21/A1 112 F1 3B/BB

35 G 22/A2 113 F2 3C/BC

36 H 23/A3 114 F3 3D/BD

37 J 24/A4 115 F4 3E/BE

38 K 25/A5 116 F5 3F/BF

39 L 26/A6 117 F6 40/C0

40 : ; 27/A7 118 F7 41/C1

41

²¢

Make/Break Code

28/A8 119 F8 42/C2

Key Number

and Symbol

Make/Break Code

¬



¯

®

4D/CD

4B/CB

48/C8

50/D0

Rev. 1.40 7 September 15, 2004