No. 6651-7/12

LC72346W, 72347W

Pin Functions

Pin No.

Pin

I/O

Function

I/O circuit

75 kHz oscillator connections

64

1

XIN

XOUT

I

O

IC testing.

These pins must be connected to ground.

—

63

2

TEST1

TEST2

I

I

Special-purpose ports for key return signal input designed with a low threshold

voltage. When a key matrix is formed in combination with port PB, simultaneous

multiple key presses with up to 3 keys can be detected. The pull-down resistors are

set up for all four pins at the same time with the IOS instruction (PWn = 2.b1). This

setting cannot be specified for individual pins. In backup mode, these pins go to the

input disabled state, and the pull-down resistors are disabled after a reset.

6

5

4

3

PA0

PA1

PA2

PA3

I

Unbalanced CMOS outputs. These outputs are switched with the IOS 0 instruction.

Since these outputs are unbalanced, no diodes are required to prevent short circuits

due to simultaneous multiple key presses. These outputs go to the high-impedance

output state in backup mode. After a reset, they go to the high-impedance output

state and remain in that state until an output instruction (OUT, SPB, or RPB) is

executed.

10

9

8

7

PB0

PB1

PB2

PB3

O

General-purpose I/O ports.

PD0, PD1 can be used as an external interrupt port. The IOS instruction (Pwn = 4, 5)

is used for switching the general-purpose I/O port function, and these ports can be set

to input or output in 1-bit units. (0: input, 1: output)

In backup mode they go to the input disabled high-impedance state.

After a reset, they switch to the general-purpose input port function.

14

13

12

11

18

17

16

15

PC0

PC1

PC2

PC3

INT1/PD0

INT0/PD1

PD2

PD3

I/O

O

General-purpose output and beep tone output shared function ports (PE0 only). The

BEEP instruction is used to switch PE0 between the general-purpose output port and

beep tone output functions. To use PE0 as a general-purpose output port, execute a

BEEP instruction with b2 set to 0. Set b2 to 1 to use PE0 as the beep tone output

port. The b0 and b1 bits are used to select the beep tone frequency. There are two

beep tone frequencies supported.

*: When PE0 is set up as the beep tone output, executing an output instruction to PE0

only changes the state of the internal output latch, it does not affect the beep tone

output in any way. Only the PE0 pin can be switched between the general-purpose

output function and the beep tone output function; the PE1 pin only functions as a

general-purpose output. These pins go to the high-impedance state in backup

mode and remain in that state until an output instruction or a BEEP instruction is

executed. Since these ports are open-drain ports, resistors must be inserted

function after a reset.

20

19

BEEP/PE0

PE1

I/O

Shared function pins used as either general-purpose I/O ports or a serial I/O port.

When used as general-purpose I/O ports, the I/O direction can be switched in single

pin units with the IOS instruction (with Pwn = C). The IOS instruction (with Pwn = 1,

b2) is used to switch the function between the general-purpose I/O port and the serial

I/O port function. (0: general-purpose I/O port, 1: serial I/O)

In backup mode (low power mode) these pins go to the input disabled high-

impedance state. After a reset, the general-purpose input port function is selected.

27

26

25

24

PK0

SCK1/PK1

SO1/PK2

SI1/PK3

Input with built-in

pull-down resistor

N-channel open-drain

CMOS push-pull

CMOS push-pull

Continued on next page.

Unbalanced CMOS push-pull