HT6523 Datasheet, PDF (1/9 Pages) Holtek Semiconductor Inc – PS/2 Mouse Controller

HT6523
PS/2 Mouse Controller
Features
· Compatible with IBM PS/2 mouse
· Integrated oscillator circuit with external resistor
· 6MHz clock frequency
· Minimal external components
· Three key-switches and four photo-coupler inputs
· Supports test mode operation
· 16-pin DIP package
General Description
The HT6523 is a PS/2 compatible mouse controller IC.
Capable of driving up to 3 key-switches and 4
photo-couplers directly into a 6-pin connector line.
Pin Assignment
NC
TEST
RESET
O SC
NC
C LK
D ATA
VSS
1
16 V D D
2
15 Y 2
3
14 Y 1
4
13 X 2
5
12 X 1
6
11 LB
7
10 M B
8
9 RB
H T6523
1 6 D IP -A
Pin Description
Pin No. Pin Name
1, 5
NC
2
TEST
3
RESET
4
OSC
6
CLK
7
DATA
8
VSS
9
RB
10
MB
11
LB
12
X1
13
X2
14
Y1
15
Y2
16
VDD
I/O
Description
¾ No connection
I
If TEST is floating or connected to VSS, then the chip is under normal opera-
tion. If TEST is connected to VDD, it will operate under the TEST mode.
I Input to reset internal LSI
I
OSC is connected to an external resistor then to VDD to generate a 6MHz sys-
tem clock.
I/O
Synchronous clock signal. The mouse generates a clock signal when sending
data to and receiving data from the system.
I/O Bidirectional data transmission line
¾ Negative power supply, ground
In the non-active state these 3 switch inputs are pulled low. To activate they
must be connected to VDD.
I In the TEST mode, MB, LB will indicate the condition of the X1, X2 inputs, if RB
is left floating or connected to VSS. Also in the TEST mode, if RB is connected
to VDD then MB and LB will indicate the condition of the Y1 and Y2 inputs.
I
Mouse interface input terminal. Four photo-coupler signals denote UP, DOWN,
LEFT and RIGHT state.
¾ Positive power supply
Rev. 1.20
1
March 6, 2003