EM78P157N
8-Bit Microcontroller with OTP ROM
3.2 Pin Descriptions
3.2.1 EM78P157NBP and EM78P157NBM Pin Descriptions
Symbol Pin No.
VDD
OSCI
10
12
Type
–
I
Function
Power supply
XTAL type: Crystal input terminal or external clock input pin
ERC type: RC oscillator input pin
XTAL type: Output terminal for crystal oscillator or external clock input pin
RC type: Instruction clock output
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
Input pin with Schmitt trigger. If this pin remains at logic low, the controller
will also remain at reset condition.
P50~P53 are bi-directional I/O pins
P50 and P51 can also be defined as the R-option pins
P50~P52 can be set as pull-down by software
P60~P61 are bi-directional I/O pins
These pins can be set as pull-high, pull-down, or open-drain through
software programming
P66~P67 are bi-directional I/O pins
These pins can be set as pull-high or open-drain through software
programming
External interrupt pin triggered by falling edge
Ground
OSCO
11
I/O
TCC
/RESET
P50~P53
3
4
13, 14,
1, 2
6~7
I
I
I/O
P60~P61
I/O
P66~P67
/INT
VSS
8~9
6
5
I/O
I
–
3.2.2 EM78P157NAP and EM78P157NAM Pin Descriptions
Symbol Pin No.
VDD
OSCI
14
16
Type
–
I
Function
Power supply
XTAL type: Crystal input terminal or external clock input pin
ERC type: RC oscillator input pin
XTAL type: Output terminal for crystal oscillator or external clock input pin
RC type: Instruction clock output
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
Input pin with Schmitt trigger. If this pin remains at logic low, the controller
will also remain at reset condition.
P50~P53 are bi-directional I/O pins
P50 and P51 can also be defined as the R-option pins
P50~P52 can be set as pull-down by software
P60~P67 are bi-directional I/O pins
These pins can be set as pull-high or open-drain through software
programming
P60~P63 can also be set as pull-down by software
External interrupt pin triggered by falling edge
Ground
OSCO
15
I/O
TCC
/RESET
P50~P53
3
4
17,18,
1, 2
I
I
I/O
P60~P67
/INT
VSS
6~13
6
5
I/O
I
–
Product Specification (V1.0) 09.22.2005
(This specification is subject to change without further notice)
•
3
EMC [ ELAN MICROELECTRONICS CORP ]
