No. 6472-7/14

LC72348G/W, 72349G/W

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 during normal operation.

—

63

2

TEST1

TEST2

I

I

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

When used in conjunction with port PB to form a key matrix, up to 3 simultaneous key

presses can be detected. The four pull-down resistors are selected together in a

single operation using the IOS instruction (PWn = 2, b1); they cannot be specified

individually. Input is disabled in backup mode, and the pull-down resistors are

disabled after a reset.

6

5

4

3

PA0

PA1

PA2

PA3

I

General-purpose CMOS and n-channel open-drain output shared-function ports.

The IOS instruction (Pwn = 2) is used for function switching.

(b0: PB0, b2: PB1, b3: PB2, PB3) (0: general-purpose CMOS, 1: n-channel open-

drain)

Special-purpose key source signal output ports. Since unbalanced CMOS output

transistor circuits are used, diodes to prevent short-circuits when multiple keys are

pressed are not required. These ports go to the output high-impedance state in

backup mode. These ports go to the output high-impedance state after a reset and

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

*: Verify the output impedance conditions carefully if these pins are used for functions

other than key source outputs.

10

9

8

7

PB0

PB1

PB2

PB3

O

General-purpose I/O ports.

PD0 can be used as an external interrupt port. Input or output mode can be set

individually using the IOS instruction by the bit (Pwn = 4, 5). A value of 0 specifies

input, and 1 specifies output. These ports go to the input disabled high-impedance

state in backup mode. They are set to function as general-purpose input ports after a

reset.

14

13

12

11

18

17

16

15

PC0

PC1

PC2

PC3

INT/PD0

PD1

PD2

PD3

I/O

General-purpose output ports with shared beep tone output function (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

Input with built-in

pull-down resistor

Unbalanced CMOS push-

pull/n-channel open-drain

N-channel open-drain

CMOS push-pull

Continued on next page.