SILAN SC84502

Silan
Semiconductors SC84502
PS/2 MOUSE CONTROLLER
DESCRIPTION
The SC84502 Mouse Controller is specially designed to control
PS/2 mouse device. This single chip can interface three keyswitches and four photo-couples direct to 8042. SC84502 can
DIP-14
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
DIP-16
amount of energy. The SC84502 PS/2 mouse controller provides
noise immunity circuits to eliminate these noise In order to reduce
energy consumption.
ORDERING INFORMATION
FEATURES
* Being compatible with PS/2 mouse mode
* Built-in noise immunity circuit
SC84502AP
DIP-14 PACKAGE
SC84502BP
DIP-16 PACKAGE
* Low power dissipation
* RC oscillation
* Three key-switches and four photo-couples inputs
APPLICATIONS
* Both key-press and key-release debounce interval 12ms
* Optical mouse or pen-mouse
* Through three key-switches input, SC84502 can exert seven
* Mechanical mouse or pen-mouse
different output
* Optomechanical mouse or pen-mouse
* The motion detector of the SC84502 could sense 8m/sec
maximum with 200 DPI wheels
* Mechanical track ball
* Optomechanical track ball
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
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Silan
Semiconductors SC84502
PIN CONFIGURATIONS
14
OSCR
OP
2
13
Y2
OSC OUT
3
CLK
4
DATA
5
VSS
6
R
12
Y1
11
X2
10
X1
9
7
8
VDD
1
16
OSCR
OP
2
15
Y2
NC
3
14
Y1
NC
4
13
X2
OSC OUT
5
12
X1
SC84502BP
1
SC84502AP
VDD
CLK
6
11
L
DATA
7
10
M
VSS
8
9
R
L
M
X2
13
Y1
14
Y2
15
L
11
M
10
R
9
OSCR
OSC OUT
COUNTER
DATA CONVERTER
12
TIMING
CONTROLLER
16
VDD
8
VSS
3
NC
4
NC
DATA
I/O
SYSTEM
CLOCK
GENERATOR
5
1
COMMAND DECODER
X1
NOISE IMMUNTY
2
DEBOUNCE
OP
MOTION DETECTOR
BLOCK DIAGRAM( Refer to SC84502BP )
7
6
DATA
CLK
DC ELECTRICAL CHARACTERISTICS (Tamb=25~70°C)
Parameter
Symbol
Condition
Min
Typ
Max
4.5
5
5.5
V
No Load
--
--
1.2
mA
Ipl
--
70
--
--
µA
Iph
--
--
--
106
µA
Operating Voltage
VDD
--
Operating Current
Iop
X1,X2,Y1,Y2
Low Input reference current
X1,X2,Y1,Y2
High Input reference current
Unit
(to be continued)
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Semiconductors SC84502
(continued)
Parameter
X1,X2,Y1,Y2 input current
CLK, DATA positive-going
threshold voltage
CLK, DATA negative-going
threshold voltage
Symbol
Min
Typ
Max
Unit
Schmitt trigger input, Ipl=76µA
0.8
--
1.2
V
Comparator input, Ipl=80µA
0.8
--
1.2
V
Comparator input, Ipl=500µA
1.5
--
2.1
V
Vt+
--
3.2
--
3.8
V
Vt-
--
1.2
--
1.9
V
V
Vpl
Condition
Low Input Voltage, Other Pins
Vail
--
--
--
1.5
High Input Voltage, Other Pins
Vaih
--
3.5
--
--
V
Imi
Pull Up Resistor, Vin=5V
16.6
--
50
µA
Idc
Vin = 0V
0.56
--
1.86
mA
Vprl
Iprl = -2 mA
--
--
0.4
V
Vin = 0V
0
--
1.0
µA
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
Iil
Input Leakage Current
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)
Symbol
Min
Typ
Max
Unit
Oscillating Frequency
Parameter
Fosc
34.3-10%
34.3
34.3+10%
kHz
Key Debounce
Tkd
--
12
--
ms
Rising Edge Crossed Width Fosc=35 kHz
Tr
14.3
--
--
µs
Falling Edge Crossed Width Fosc=35 kHz
Tf
14.3
--
--
µs
Mouse CLK Active Time
Tmca
--
42.9
--
µs
Mouse CLK Inactive Time
Tmci
--
42.9
--
µs
Time that Mouse Sample DATA from CLK rising Edge
Tmdc
--
14.3
--
µs
System CLK Active Time
Tsca
--
42.9
--
µs
System CLK Inactive Time
Tsci
--
42.9
--
µs
Time from DATA Transition to Falling Edge of CLK
Tsdc
--
14.3
--
µs
Time from rising Edge of CLK to DATA Transition
Tscd
--
28.6
--
µs
Tpi
0
--
50
µs
Time to mouse Inhibit after the 11th CLK to
ensure mouse does not start another Transmission
Note: The AC timings are measured under using 35kHz system clock signal.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
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Semiconductors SC84502
X1, X2, Y1, Y2 INPUT IMPEDANCE
UNIT:KΩ
16.0
MAX.
15.0
14.0
TYP.
13.0
12.0
11.0
MIN.
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0
1.0
2.0
3.0
4.0
5.0
INPUT VOLTAGE
PIN DESCRIPTION (refer to SC84502BP)
Pin No.
Pin Name
I/O
1
VDD
--
2
OP
I
3
NC
--
Description
Positive Power Supply.
X, Y inputs:
Floating: Comparator input.
GND: Schmitt trigger input.
Short to OSC OUT: Testing Mode.
No Connection
4
NC
--
No Connection
5
OSCOUT
O
Clock output.
6
CLK
I/O
8042 auxiliary port CLK line.
7
DATA
I/O
8042 auxiliary port DATA line.
8
VSS
--
9
R
10
M
11
L
12
X1
13
X2
Negative Power Supply
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
14
Y1
15
Y2
16
OSCR
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.
I
50kΩ ± 5% pull low for 35kHz oscillation
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Semiconductors SC84502
FUNCTION DESCRIPTIONS
1. OPERATING MODE
There are four operating modes in PS/2 mouse:
i) Reset Mode:
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:
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Semiconductors Byte
Bit
1
0
SC84502
Description
Left button status; 1 = pressed
1
Right button status; 1 = pressed
2
Middle button status; 1 = pressed
3
Reserve
4
X data sign; 1 = negative
5
Y data sign; 1 = negative
6
X data overflow; 1 = overflow
7
Y data overflow; 1 = overflow
2
0-7
X data(D0 ~ D7)
3
0-7
Y data(D0 ~ D7)
3.PS/2 MOUSE DATA TRANSMISSION
i) SC84502 generates the clocking signal when sending data to and receiving data from the system.
ii) The system requests SC84502 receive system data output by forcing the DATA line to an inactive level and
allowing CLK line to go to an active level.
iii) Data transmission frame:
Bit
Function
1
Start bit(always 0)
2~9
Data bits(D0 ~D7)
10
Parity bit(odd parity)
11
Stop bit (always 1)
iv) Data Output (data from SC84502 to system)
If CLK is low (inhibit status), data is no transmission.
If CLK is high and DATA is low(request-to-send), data is updated. Data is received from the system and no
transmission are started by SC84502 until CLK and DATA both high. If CLK and DATA are both high, the
transmission is ready. DATA is valid prior to the falling edge of CLK and beyond the rising edge of CLK.
During transmission, SC84502 check for line contention by checking for an inactive level on CLK at
intervals not to exceed 100µ sec. Contention occurs when the system lowers CLK to inhibit SC84502
output after SC84502 has started a transmission. If this occurs before the rising edge of the contention
does not occur by the tenth clock, the transmission is complete.
Following a transmission, the system inhibits SC84502 by holding CLK low until it can service the input or
until the system receives a request to send a response from SC84502.
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Semiconductors SC84502
v) Data Input (from system to SC84502)
System first check if SC84502 is transmitting data. If SC84502 is transmitting, the system can override the
output forcing CLK to an inactive level prior to the tenth clock. If SC84502 transmission is beyond the tenth
clock, the system receives the data. If SC84502 is not transmitting or if the system choose to override the
output, the system force CLK to an inactive level for a period of not less than 100m sec while preparing for
output. When the system is ready to output start bit (0), it allows CLK go to active level. If request-to-send is
detected, SC84502 clocks 11 bits. Following the tenth clock SC84502 checks for an active level on the
DATA line, and if found, force DATA low , and clock once more. If occurs framing error, SC84502 continue
to clock until DATA is high, then clocks the line control bit and request a Resend. When the system sends
out a command or data transmission that requires a response, the system waits for SC84502 to response
before sending its next output.
4. PS/2 MOUSE ERROR HANDLING
i) A Resend command ( FE ) following receipt of an invalid input or any input with incorrect parity.
ii) If two invalid input are received in succession, an error code of hex FC send to the system.
iii) The counter accumulators are cleared after receiving any command except “Resend”.
iv) SC84501 receives a Resend command ( FE ), it transmit its last packet of data.
vIn the stream mode “Resend” is received by SC84502 following a 3-byte data packet transmission to the
system. SC84502 resend the 3-byte data packet prior to clearing the counter.
vi) A response is sent within 25 ms if
a). The system requires a response
b). An error is detected in the transmission
vii). When a command requiring a response is issued by the system ,another command should not be issue until
either the response is received or 25ms has passed.
5. PS/2 MOUSE COMMANDS DESCRIPTION
There are 16 valid commands that transmits between the system and SC84502. The “FA” code is always the
first response to any valid input received from the system other than a Set Wrap Mode or Resend command.
The following table list the commands:
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Semiconductors Hex Code
SC84502
Command
SC84502 echo code
FF
Reset
FA, AA, 00
FE
Resend
XX, (XX, XX)
F6
Set Default
FA
F5
Disable
FA
F4
Enable
FA
F3, XX
Set Sampling Rate
FA, FA
F2
Read Device Type
FA, 00
F0
Set Remote Mode
FA
EE
Set Wrap Mode
FA
EC
Reset Wrap Mode
FA
EB
Read Data
FA, XX, XX, XX
EA
Set Stream Mode
FA
E9
Status Request
FA, XX, XX, XX
E8, XX
Set Resolution
EA, FA
E7
Set Autospeed
FA
E6
Reset Autospeed
FA
The following describes valid commands:
a). Reset ( FF )
SC84502 operation:
i). Completion the reset.
ii). Transmitted FA,AA,00 to the system.
iii). Set default:
sampling rate: 100 reports/s
non-autospeed
stream mode
2 dots/count
disable
b). Resend ( FE )
i). Any time SC84502 receives an invalid command, it returns a Resend command to the system.
ii). When SC84502 receives a Resend command, it retransmits its last packet of data. If the last packet
was a Resend command, it transmits the packet just prior to the Resend command.
iii). In stream mode, if a Resend command is received by SC84502 immediately following a 3-byte data
packet transmission to the system.
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Semiconductors SC84502
c). Set Default (F6)
The command reinitializes all conditions to the power-on defaults.
d). Disable (F5)
This command is used in the stream mode to stop transmissions from SC84502.
e). Enable (F4)
Begins transmissions, if in stream mode.
f). Set Sampling Rate (F3, XX)
In the stream mode, this command sets the sampling rate to the value indicated by byte hex XX, shown in
following:
Second byte XX
Sample Rate
0A
10/sec
14
20/sec
28
40/sec
3C
60/sec
50
80/sec
64
100/sec
C8
200/sec
g). Read Device Type (F2)
SC84502 always echoes “FA, 00 “ following this command.
h). Set Remote Mode (F0)
Data values are reported only in response to a Read Data command.
i). Set Wrap Mode (EE)
Wrap mode remains until Reset (FF) or Reset Wrap Mode (EC) is received.
j). Reset Wrap Mode (EC)
SC84502 returns to the previous mode of operation after receiving this command.
k). Read Data (EB)
This command is executed in either remote or stream mode. The data is transmitted even if there has been
no movement since the last report or the button status is unchanged. Following a Read Data command, the
registers are cleared after a data transmission.
l). Set Stream Mode (EA)
This command sets SC84502 in stream mode.
m). Status Request (E9)
When this command is issued by the system, SC84502 respond with a 3-byte status report as follows:
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Semiconductors SC84502
Byte
Bit
1
0
1=Right button pressed
Description
1
1=Middle button pressed
2
1= Left button pressed
3
Reserved
4
0=Normal speed, 1=Autospeed
5
0=Disabled, 1=Enabled
6
0=Stream mode, 1=Remote mode
7
Reserved
2
0–7
Current resolution setting (D0-D7)
3
0-7
Current sampling rate (D0-D7)
n). Set Resolution ( E8,XX )
SC84502 provides four resolutions selected by the second byte of this command as follows:
Second Byte XX
Resolution
00
8 dot/count
01
4 dot/count
02
2 dot/count
03
1 dot/count
o). Set Autospeed ( E7 )
At the end of a sample interval in the stream mode, the current X and Y data values are converted new
values. The sign bits are not involved in this conversion. The conversion is only in stream mode. The
relationship between the input and output count follows:
Input
Output
0
0
1
1
2
1
3
3
4
6
5
9
N (≥6)
2.0*N
p). Reset Autospeed ( E6 )
This command restore normal speed.
6.TESTING MODE
Whenever OPT is connected to OSC OUT, the chip will enter buyer's testing mode. The X direction output signals
of comparators will present to L and M pin. Pressing "R" key can toggle the output from X direction to Y direction.
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Semiconductors SC84502
TIMING DIAGRAM
(1) Photo-couples pulse width
X1(Y1)
X2(Y2)
Tr
Tf
(2) PS/2 Mouse
(A) Receiving Data
1st
CLK
Inhibit
CLK
2rd
CLK
9th
CLK
10th
CLK
11th
CLK
Tmca
Tmci
DATA
Tmdc
Start
Bit
Bit0-Bit7
Parity
Bit
Stop
Bit
Line
Control
Bit
(B) Sending Data
1st
CLK
CLK
2nd
CLK
Tscl
10th
CLK
11th
CLK
Tsca
Tpi
Tsdc
DATA
Tscd
Start
Bit
Bit0-Bit7
Parity
Bit
Stop
Bit
AC TIMING POINT
Output:
DATA
CLK PIN(PS/2 mouse mode)
VDD-2.6
VSS+0.4
VSS+1.6
Input:
VSS
X1, X2, Y1, Y2 PIN
VDD-0.8
VSS+0.8
CLK, DATA PIN
VDD
L, M, R PIN
VSS
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Semiconductors SC84502
SC84502 I/O PIN EQUIVALENT CIRCUITS
CLK:
X1,X2,Y1,Y2:
X1,X2,Y1,Y2
MOUSE DIGITAL SIGNAL
VCC
VCC
13.2kΩ
PS/2 MOUSE ENABLE
CLK
DATA INPUT SIGNAL
VCC
DATA INPUT SIGNAL
VCC
VPP/4
13.2kΩ
10kΩ
R, M, L:
DATA:
VCC
(R,M,L)
(R, L, M)
INTERNAL SIGNAL
VCC
DATA
PS/2 MOUSE ENABLE
DATA INPUT SIGNAL
DATA INPUT SIGNAL
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Semiconductors SC84502
APPLICATIONS CIRCUITS
2
16
OP
NC
4
NC
5
OSC OUT
CLK
6
CLK
DATA
7
DATA
8
Vss
GROUND
1
+5V
OSC DR
3
50k¡
VDD
Y2
15
Y1
14
X2
13
X1
12
L
11
M
10
R
9
10µf
510¡
510¡
SC84502AP
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Semiconductors SC84502
PACKAGE OUTLINE
DIP-14-300-2.54
UNIT:mm
7.62
6.40
0.25
2.54
1.50
15 degree
3.30
5.08
3.51
19.4
0.46
DIP-16-300-2.54
UNIT:mm
7.62
6.40
0.25
2.54
1.50
15 degree
3.30
5.08
3.51
19.4
0.46
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
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