EM84520
2-IN-ONE SCROLLING MOUSE CONTROLLER
FUNCTIONAL BLOCK DIAGRAM
THREE TYPES SELECTOR
DATA/RXD
CLK/RTS
Z1
Z2
VOLTAGE
SENSOR
KEY-SWITCH
DETECTOR
COMPARATOR
Z-AXIS COUNTER
C
O
M
P
A
R
A
T
O
R
OPT
X1
D
E
T
E
C
T
O
R
M
O
T
I
O
N
DATA
I/O
COUNTER
MULTIPLEXER
X2
Y1
Y2
D
E
B
O
U
N
C
E
L
M
COMMAND
STATUS
TIMING
CONTROLLER
R
SYSTEM CLOCK
GENERATOR
OSCR
OSC.OUT
RC
OSCILLATION
PIN DESCRIPTIONS
Symbol
I/O
I/O
Function
INPUT: 200kohm pull low to VSS.
OPT
When OPT is connected to VDD, EM84520 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 or Z1,Z2 respectively.
OUTPUT: 2kHz Z-axis LED driving source with A/D/E/F version.
"1"= VDD, "0"= floating
High duty is about 60us.
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 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.
Connect to 8042 auxiliary port DATA line in PS/2 mode or connect directly to RS-
232C RXD pin in serial mode.
DATA/RXD
I/O
R
M
L
I
Three key-switches inputs. 200kΩ resistor pull low.
In Z-axis key mode, M key toggling can change the scrolling speed from low to
high.
I/O
I/O
X1
X2
Y1
Y2
Z1
Z2
I
I
I
I
I
I
Three step dynamic input impedance. If OSC.OUT is not connected to LEDs, the
dynamic input impedance will be off.
Use current comparator to measure photo-couples "ON", or "OFF".
Z-axis input.
Photo mode : Three steps dynamic input impedance. Current comparator input.
Key mode : 200 kΩ resistor pull low. 7 levels increased by "M" key.
Voltage mode : 200 kΩ resistor pull low. 7 levels voltage comparator.
Mechanical mode : 13.2kΩ resistor pull low. Current comparator input.
Negative power.
VSS
VDD
Power line.
6.28.1999
* This specification are subject to be changed without notice.
2
ELAN [ ELAN MICROELECTRONICS CORP ]
