EM78452
8-Bit Microcontroller
4 Pin Description
Symbol Pin No. Type
Function Description
8-bit bidirectional general-purpose I/O port. All of its pins can be
pulled-high individually by software.
P50~P57 11~18
P60~P67 27~34
P70~P72 37~35
I/O
I/O
I/O
8-bit bidirectional general-purpose I/O port. All of its pins can be
pulled-high by software, and pin-change wake-up pins.
LED direct-driving pins with internal serial resistor used as
output and is software defined.
8-bit bidirectional general-purpose I/O port. All of its pins can be
pulled-high by software. P80 and P81 are also used as R-option
pins.
P80~P87 19~26
P90~P95 5~10
I/O
I/O
6-bit bidirectional general-purpose I/O port. All of its pins can be
pulled-high by software. P90 and P91 are pin-change wake-up
pins.
LED direct-driving pin with internal serial resistor used as output
and is software defined.
Code option Bit 3 (REN): reset enable
REN=0 → for reset pin
P70/
37
I/O
RESET
REN=1 → for general purpose I/O (P70)
Internal pull high resistor 220KΩ
Crystal input
R-OSCI
OSCO
39
40
I
Crystal output
O
By connecting P74 and P76 together, P74 can be pulled-high
by software and it is also a pin-change wake-up pin.
CLK
4
3
I/O
I/O
P76 can be defined as an open-drain output.
By connecting P75 and P77 together, P75 can be pulled-high
by software and it is also a pin-change wake-up pin.
DATA
P77 can be defined as an open-drain output.
Power supply pin
VDD
VSS
38
1
−
−
Ground pin
Interrupt Schmitt trigger pin.
The interrupt function is triggerred at a falling edge.
Users can enable it by software.
/INT
2
I
Slave Ready pin for SPI
Serial data in for SPI
Serial data out for SPI
Serial clock for SPI
SRDY
SDI
6
7
I/O
I/O
I/O
I/O
I/O
SDO
SCK
/SS
8
9
/Slave select for SPI
10
Product Specification (V1.0) 10.18.2007
(This specification is subject to change without further notice)
• 3
ELAN [ ELAN MICROELECTRONICS CORP ]
