EM78F651N
8-Bit Microcontroller
4 Pin Description
Table 1 EM78F651NAP, EM78F651NAM
Symbol
Pin No.
Type
Function
Bidirectional 2-bit input/output pins
13, 14
I/O
P54~P55
Bidirectional 8-bit input/output pins. These can be pulled-high or can
be open drain by software programming. P60~63 can also be pulled
down by software.
4~11
I/O
P60~P67
1
I/O
I
P77
P77 is an open drain I/O pin.
Crystal type: Crystal input terminal or external clock input pin
ERC type: RC oscillator input pin
14
OSCI
Crystal type: Output terminal for crystal oscillator or external clock
input pin.
RC type: Instruction clock output.
13
I/O
OSCO
External clock signal input.
Real time clock/counter (with Schmitt Trigger input pin) must be tied
to VDD or VSS if not in use.
1
4
2
I
I
I
TCC
/INT
External interrupt pin triggered by a falling edge.
Input pin with Schmitt Trigger. If this pin remains at logic low, the
controller will also remain in reset condition.
/RESET
12
3
VDD
VSS
−
−
Power supply
Ground
Table 2 EM78F651NBP, EM78F651NBM
Symbol
Pin No.
Type
Function
Bidirectional 4-bit input/output pins
50, P53 can be pulled-down by software.
P50, P53
P54~P55
16, 1,
14, 15
I/O
Bidirectional 8-bit input/output pins. These can be pulled-high or can
be open drain by software programming. P60~63 can also be pulled
down by software.
5~12
I/O
P60~P67
2
I/O
I
P77
P77 is an open drain I/O pin.
Crystal type: Crystal input terminal or external clock input pin
ERC type: RC oscillator input pin
15
OSCI
Crystal type: Output terminal for crystal oscillator or external clock
input pin.
RC type: Instruction clock output.
14
I/O
OSCO
External clock signal input.
The real time clock/counter (with Schmitt Trigger input pin) must be
tied to VDD or VSS if not in use.
2
5
3
I
I
I
TCC
/INT
External interrupt pin triggered by a falling edge.
Input pin with Schmitt Trigger. If this pin remains at logic low, the
controller will also remain in reset condition.
/RESET
13
4
-
-
VDD
VSS
Power supply
Ground
Product Specification (V1.1) 10.20.2006
(This specification is subject to change without further notice)
• 3
ELAN [ ELAN MICROELECTRONICS CORP ]
