EM78P156N

OTP ROM

Table 2 EM78P156NAS Pin Description

 

Symbol

Pin No.

Type

Function

 

 

 

 

 

 

VDD

15

-

* Power supply.

 

OSCI

17

I

* XTAL type: Crystal input terminal or external clock input pin.

 

* ERC type: RC oscillator input pin.

 

 

 

 

 

OSCO

16

I/O

* XTAL type: Output terminal for crystal oscillator or external clock input pin.

 

* RC type: Instruction clock output.

 

 

 

 

* External clock signal input.

 

TCC

4

I

* The real time clock/counter (with Schmitt trigger input pin), must be tied to

 

VDD or VSS if not in use.

 

 

 

 

 

/RESET

5

I

* Input pin with Schmitt trigger. If this pin remains at logic low, the controller

 

will also remain in reset condition.

 

 

 

 

 

P50~P53

18, 19,

I/O

* P50~P53 are bi-directional I/O pins.

 

* P50 and P51 can also be defined as the R-option pins.

 

 

2, 3

 

* P50~P52 can be pulled-down by software.

 

 

 

 

 

 

 

 

* P60~P67 are bi-directional I/O pins.

 

P60~P67

7~14

I/O

* These can be pulled-high or can be open-drain by software programming.

 

 

 

 

* P60~P63 can also be pulled-down by software.

 

/INT

7

I

* External interrupt pin triggered by falling edge.

 

VSS

6

-

* Ground.

Table 3 EM78P156NKM Pin Description

 

 

 

 

 

 

Symbol

Pin No.

Type

Function

 

 

 

 

 

 

VDD

15,16

-

* Power supply.

 

OSCI

18

I

* XTAL type: Crystal input terminal or external clock input pin.

 

* ERC type: RC oscillator input pin.

 

 

 

 

 

OSCO

17

I/O

* XTAL type: Output terminal for crystal oscillator or external clock input pin.

 

* RC type: Instruction clock output.

 

 

 

 

* External clock signal input.

 

TCC

3

I

* The real time clock/counter (with Schmitt trigger input pin), must be tied to

 

VDD or VSS if not in use.

 

 

 

 

 

/RESET

4

I

* Input pin with Schmitt trigger. If this pin remains at logic low, the controller

 

will also remain in reset condition.

 

 

 

 

 

 

19, 20,

 

* P50~P53 are bi-directional I/O pins.

 

P50~P53

I/O

* P50 and P51 can also be defined as the R-option pins.

 

 

1, 2

 

* P50~P52 can be pulled-down by software.

 

 

 

 

 

P60~P67

7~14

I/O

* P60~P67 are bi-directional I/O pins.

 

* These can be pulled-high or can be open-drain by software programming.

 

 

 

 

* P60~P63 can also be pulled-down by software.

 

/INT

7

I

* External interrupt pin triggered by falling edge.

 

VSS

5, 6

-

* Ground.

This specification is subject to change without prior notice. 7

07.29.2004 (V1.2)