Silan
Semiconductors
PS/2 MOUSE CONTROLLER
DESCRIPTION
The SC84502 Mouse Controller is specially designed to control
PS/2 mouse device. This single chip can interface three key-
switches and four photo-couples direct to 8042. SC84502 can
receive command and echo status or data format which are
compatible with IBM PS/2 mode mouse. Key debouncing circuit is
provided to prevent false entry and improve the accuracy.
In the conventional mouse, a great number of noises are
generated when the grid is partially closed or opened. These noise
are usually mistaken for movement signals by conventional mouse
controller and the cursor of the display screen is thus moved
frequently up and down or back and forth. This will consumes a great
amount of energy. The SC84502 PS/2 mouse controller provides
noise immunity circuits to eliminate these noise In order to reduce
energy consumption.
SC84502
DIP-14
DIP-16
FEATURES
* Being compatible with PS/2 mouse mode
* Built-in noise immunity circuit
* Low power dissipation
* RC oscillation
* Three key-switches and four photo-couples inputs
* Both key-press and key-release debounce interval 12ms
* Through three key-switches input, SC84502 can exert seven
different output
* The motion detector of the SC84502 could sense 8m/sec
maximum with 200 DPI wheels
ORDERING INFORMATION
SC84502AP
SC84502BP
DIP-14 PACKAGE
DIP-16 PACKAGE
APPLICATIONS
* Optical mouse or pen-mouse
* Mechanical mouse or pen-mouse
* Optomechanical mouse or pen-mouse
* Mechanical track ball
* Optomechanical track ball
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
1
Silan
Semiconductors
PIN CONFIGURATIONS
VDD
OP
OSC OUT
CLK
DATA
VSS
R
SC84502
14
13
VDD
OSCR
OP
Y2
NC
Y1
NC
X2
OSC OUT
X1
CLK
L
DATA
M
VSS
1
2
3
4
5
6
7
SC84502AP
1
2
SC84502BP
3
4
5
6
7
8
16
15
14
13
12
11
10
9
OSCR
Y2
Y1
X2
X1
L
M
R
12
11
10
9
8
BLOCK DIAGRAM
( Refer to SC84502BP )
OP
X1
X2
Y1
Y2
2
NOISE IMMUNTY
1
MOTION DETECTOR
COUNTER
V
DD
V
SS
NC
NC
12
13
14
15
11
10
9
8
3
4
COMMAND DECODER
DATA CONVERTER
DEBOUNCE
L
M
R
TIMING
CONTROLLER
OSCR
16
5
OSC OUT
SYSTEM
CLOCK
GENERATOR
DATA
I/O
7
DATA
6
CLK
DC ELECTRICAL CHARACTERISTICS
(Tamb=25~70°C)
Parameter
Operating Voltage
Operating Current
X1,X2,Y1,Y2
Low Input reference current
X1,X2,Y1,Y2
High Input reference current
Symbol
V
DD
Iop
Ipl
Iph
--
No Load
--
Condition
Min
4.5
--
70
--
Typ
5
--
--
--
Max
5.5
1.2
--
106
Unit
V
mA
µA
µA
--
(to be continued)
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
2
Silan
Semiconductors
(continued)
SC84502
Symbol
V
pl
Parameter
X1,X2,Y1,Y2 input current
Condition
Schmitt trigger input, Ipl=76µA
Comparator input, Ipl=80µA
Comparator input, Ipl=500µA
Min
0.8
0.8
1.5
3.2
1.2
--
3.5
16.6
0.56
--
0
Typ
--
--
--
--
--
--
--
--
--
--
--
Max
1.2
1.2
2.1
3.8
1.9
1.5
--
50
1.86
0.4
1.0
Unit
V
V
V
V
V
V
V
µA
mA
V
µA
CLK, DATA positive-going
threshold voltage
CLK, DATA negative-going
threshold voltage
Low Input Voltage, Other Pins
High Input Voltage, Other Pins
L,M,R Input Current
PS/2 mouse mode
DATA,CLK input Current
PS/2 mouse mode
DATA,CLK low output Voltage
L,M,R,X1,X2,Y1,Y2
Input Leakage Current
Vt+
Vt-
Vail
Vaih
Imi
Idc
Vprl
Iil
--
--
--
--
Pull Up Resistor, Vin=5V
Vin = 0V
Iprl = -2 mA
Vin = 0V
Note: All voltages in above table are compared with VSS.
All parameters in above table are tested under VDD=5V.
CLK & DATA output gates are open drains that connect to pull up resistors.
AC ELECTRICAL CHARACTERISTICS
( Tamb = 0 ~ 70°C)
Parameter
Oscillating Frequency
Key Debounce
Rising Edge Crossed Width Fosc=35 kHz
Falling Edge Crossed Width Fosc=35 kHz
Mouse CLK Active Time
Mouse CLK Inactive Time
Time that Mouse Sample DATA from CLK rising Edge
System CLK Active Time
System CLK Inactive Time
Time from DATA Transition to Falling Edge of CLK
Time from rising Edge of CLK to DATA Transition
Time to mouse Inhibit after the 11th CLK to
ensure mouse does not start another Transmission
Symbol
Fosc
Tkd
Tr
Tf
Tmca
Tmci
Tmdc
Tsca
Tsci
Tsdc
Tscd
Tpi
Min
34.3-10%
--
14.3
14.3
--
--
--
--
--
--
--
0
Typ
34.3
12
--
--
42.9
42.9
14.3
42.9
42.9
14.3
28.6
--
Max
34.3+10%
--
--
--
--
--
--
--
--
--
--
50
Unit
kHz
ms
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
Note: The AC timings are measured under using 35kHz system clock signal.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
3
Silan
Semiconductors
X1, X2, Y1, Y2 INPUT IMPEDANCE
UNIT:K
SC84502
16.0
15.0
14.0
13.0
12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0
MAX.
TYP.
MIN.
1.0
2.0
3.0
4.0
5.0
INPUT VOLTAGE
PIN DESCRIPTION
(refer to SC84502BP)
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin Name
V
DD
OP
NC
NC
OSCOUT
CLK
DATA
V
SS
R
M
L
X1
X2
I/O
--
I
--
--
O
I/O
I/O
--
No Connection
No Connection
Clock output.
8042 auxiliary port CLK line.
8042 auxiliary port DATA line.
Negative Power Supply
Positive Power Supply.
X, Y inputs:
Description
Floating: Comparator input.
GND: Schmitt trigger input.
Short to OSC OUT: Testing Mode.
Three key-switches esert seven different combinations totally. Both key-pressed
and key-released signals will be sent accompanied with horizontal and vertical
I
state. The status of the key-switches will be preserved, whenever the value of
horizontal or vertical counters will present at DATA. And the debounce interval for
both key-press and key release is 12ms.
Four photo-couple signal denote UP, DOWN, LEFT and RIGHT state.
I
During the scanning period, as long as the photo-couples change their states, the
value of vertical or horizontal, counter will increase or decrease accordingly.
50kΩ
±
5% pull low for 35kHz oscillation
Y1
Y2
OSCR
I
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
4
Silan
Semiconductors
FUNCTION DESCRIPTIONS
1. OPERATING MODE
There are four operating modes in PS/2 mouse:
i) Reset Mode:
SC84502
In this mode a self-test is initiated during power-on or by a Reset command. After reset signal, PS/2 mouse
will send:
1) Completion code AA&ID code 00.
2) Set default:
sampling rate: 100 reports/s
non-autospeed
stream mode
2 dot/count
disable
ii) Stream Mode:
The maximum rate of transfer is the programmed sample rate.
Data report is transmitted if
1) switch is pressed
2) movement has been detect
iii) Remote Mode:
Data is transmitted only in response to a Read Data command.
iv) Wrap Mode:
Any byte of data sent by the system, except hex EC(Reset wrap mode) or hex FF(Reset), is returned by
SC84502.
2. PS/2 MOUSE DATA REPORT
i) In stream mode: A data report is sent at the end of a sample interval.
ii)In remote mode: A data report is sent in response to Read Data command.
iii) Data report format:
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
5
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