ELAN EM84530 Datasheet
GENERAL DESCRIPTION
The EM84530 Mouse Controller is specially designed to control serial mouse or PS/2 mouse device.
This single chip can interface three key-switches and 4 X-Y photo-couples directly to RS-232C or 8042
controller.
FEATURES
• Include PnP software scrolling function
• Using 50kΩ ±1% resistor for RC oscillation.
• Compatible with legacy PS/2 mouse.
• Compatible with Microsoft serial mouse.
• Compatible with Microsoft PS/2 mouse.
• Serial or PS/2 port auto-detect.
• 100 bytes PnP ID code could be filled by code layer.
• Built-in noise immunity circuit.
• The sampiling rate of motion detector is up to 65KHz.
• Built-in three zener diodes : one in VDD to VSS, two in RTS to VDD.
• CMOS push-pull RXD output.
• Built-in current comparator for photo-couples input.
• Built-in three step dynamic input impedance.
• Three key-switches and four photo-couples inputs.
• RTS debouncing circuit included.
• Photo couple test mode included.
• Low power dissipation.
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EM84530
2-IN-ONE MOUSE CONTROLLER
APPLICATION
• Serial PnP mouse.
• PS/2 mouse.
• Combo mouse.
PIN ASSIGNMENT
VDD
OSC.OUT
NC
NC
CLK/RTS
DATA/RXD
OPT
VSS
EM84530
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
OSCR
Y2
Y1
X2
X1
L
M
R
* This specification are subject to be changed without notice.
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FUNCTIONAL BLOCK DIAGRAM
OPT
X1
X2
Y1
Y2
L
M
R
C
D
O
M
E
M
O
T
P
T
E
A
I
C
R
O
T
A
N
O
T
R
O
R
D
E
B
O
U
N
C
E
OSCR
OSC.OUT
COUNTER
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MULTIPLEXER
COMMAND
& STATUS
OR PNP IO
SYSTEM CLOCK
GENERATOR
RC
OSCILLATION
EM84530
2-IN-ONE MOUSE CONTROLLER
DATA/RXD
CLK/RTS
DATA
I/O
TIMING
CONTROLLER
PIN DESCRIPTIONS
Symbol I/O Function
OPT I/O INPUT: 200kΩ pull low to VSS.
When OPT is connected to VDD, EM84530 will enter test mode. In test mode,
L will be the output of X1,while M will be the output of X2. Toggling R key can
change these output to be Y1,Y2 respectively.
OSC.OUT O The RC oscillation clock output. Or 3mA sink current output for X, Y photo
emitters.
OSCR I Connect 50kΩ±1% precise resistor for oscillation.
CLK/RTS I/O Connect directly to 8042 auxiliary port CLK line in PS/2 mode or connect directly
to RS-232C RTS pin in serial mode. Auto-detect the operating port by this pin.
DATA/RXD I/O Connect directly to 8042 auxiliary port DATA line in PS/2 mode or connect
directly to RS-232C RXD pin in serial mode.
R I Three key-switches inputs. 200kΩ resistor pull low.
M I/O
L I/O
X1 I Three step dynamic input impedance. If OSC.OUT is not connected to LEDs, the
X2 I dynamic input impedance will be off.
Y1 I Use current comparator to measure photo-couples "ON", or "OFF".
Y2 I
VSS Negative power.
VDD Power line.
* This specification are subject to be changed without notice.
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FUNCTION DESCRIPTIONS
(I) Serial Mouse :
In Microsoft mode, the transmission cycle consists of four bytes in one report. Each byte contains one start
bit, 7 data bits and two stop bits. The first byte contains "L", "R" key status and four bits of the two most
significant bits in horizontal counter and vertical counter. The second byte represents the value accumulated
by horizontal counter, the third byte is the data of the vertical counter. The last byte contains only "M" key
status. The vertical data is transmitted in 2's complement.
Output byte arrange
Bit no. ...... 654321 0
1st byte ...... 1 L R V7' V6' H7 H6
2nd byte .... 0 H5 H4 H3 H2 H1 H0
3rd byte .... 0 V5' V4' V3' V2' V1' V0'
4th byte .... 0 0 M 0 0 0 0
Plug & Play ID code
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EM84530
2-IN-ONE MOUSE CONTROLLER
When RTS input from low to high, EM83810 will send a string ID code. Customer can specify the contains
of the code area and the total lenth below 100 bytes by changing the code layer.
Field Name Length Field Data Description
Other ID <17 4D, 5A, 40, 00, 00, 00 ID for legacy
Begin ID 1 08 Begin PnP ID
PnP Revision 2 01, 24 Version 1.00
EISA ID 3 25, 2D, 23 EMC
Product ID 4 10, 10, 10, 11 0001
Serial Number 9 3C None provided
Class ID <34 3C, 2D, 2F, 35, 33, 25 Mouse Class
Driver ID <42 3C, 30, 2E, 30, 10 26, 10, 21 PnP0F0A
User Name <42 3C, 25, 2D, 23, 00, 33, 23, 32, EMC SCROLLING
2F, 2C, 2C, 29, 2E, 27, 00, 33, SERIAL MOUSE
25, 32, 29, 21, 2C, 00, 2D, 2F,
35, 33, 25
Checks um 2 21, 15 2 bytes checks um
End PnP 1 09 End PnP ID
(II) Legacy PS/2 mouse operating:
(A) Operating mode
There are four operating modes in PS/2 mouse:
a. 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
(a) Send completion code AA & ID code 00.
(b) Set default :
* This specification are subject to be changed without notice.
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2-IN-ONE MOUSE CONTROLLER
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sampling rate: 100 reports/s
non-autospeed
stream mode
2 dot/count
disable
b. Stream Mode:
The maximum rate of transfer is the programmed sample rate.
Data report is transmitted if
(a) switch is pressed
(b) movement has been detect
c. Remote Mode:
Data is transmitted only in response to a Read Data command.
d. Wrap Mode:
Any byte of data sent by the system, except hex EC ( Reset wrap mode ) or hex FF ( Reset ), is returned
by EM84530.
EM84530
B). PS/2 Mouse Data Report:
a). In stream mode: A data report is sent at the end of a sample interval.
b). In remote mode: A data report is sent in response to Read Data command.
c). Data report format:
Byte Bit Description
1 0 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 )
C) PS/2 mouse Data Transmission:
a). EM84530 generates the clocking signal when sending data to and receiving data from the system.
b). The system requests EM84530 receive system data output by forcing the DATA line to an inactive level
and allowing CLK line to go to an active level.
* This specification are subject to be changed without notice.
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EM84530
2-IN-ONE MOUSE CONTROLLER
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c). 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 )
d). Data Output ( data from EM84530 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 EM84530 until CLK and DATA both high. If CLK and DATA both
are high, the transmission is ready. DATA is valid prior to the falling edge of CLK and beyond the rising edge
of CLK. During transmission, EM84530 check for line contention by checking for an inactive level on CLK
at intervals not to exceed 100u sec. Contention occurs when the system lowers CLK to inhibit EM84530
output after EM84530 has started a transmission. If this occurs before the rising edge of the tenth clock,
EM84530 internal store its data in its buffer and returns DATA and CLK to an active level. If the contention
does not occur by the tenth clock, the transmission is complete.
Following a transmission, the system inhibits EM84530 by holding CLK low until it can service the input
or until the system receives a request to send a response from EM84530.
e). Data Input ( from system to EM84530 ):
The system first check if EM84530 is transmitting data. If EM84530 is transmitting, the system can override
the output forcing CLK to an inactive level prior to the tenth clock. If EM84530 transmission is beyond
the tenth clock, the system receives the data. If EM84530 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 100µ 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, EM84530 clocks 11 bits. Following the tenth clock EM84530 checks for
an active level on the DATA line, and if found, force DATA low , and clock once more. If occurs framing
error, EM84530 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 EM84530 to response before sending its next output.
D). PS/2 Mouse Error Handling:
a). A Resend command ( FE ) following receipt of an invalid input or any input with incorrect parity.
b). If two invalid input are received in succession, an error code of hex (FC) is send to the system.
c). The counter accumulators are cleared after receiving any command except “Resend”.
d). EM84530 receives a Resend command ( FE ), it transmit its last packet of data.
e). In the stream mode “Resend” is received by EM84530 following a 3-byte data packet transmission
to the system. EM84530 resend the 3-byte data packet prior to clearing the counter.
* This specification are subject to be changed without notice.
6.28.1999
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