4501 datasheet(121/212 Pages) RENESAS

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2.1 I/O pins

2-4

Rev.2.01

Feb 07, 2005

4501 Group

APPLICATION

REJ09B0192-0201

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Port C

Port C is a 1-bit I/O port.

s Input/output of port C

q Data input to port C

Set the output latch of specified port C to “1” with the SCP instruction. If the output latch is set

to “0,” “L” level is input.

When the SNZCP instruction is executed, if the port C is “1,” the next instruction is skipped.

If it is “0,” the next instruction is executed.

q Data output from port C

Set the output level to the output latch with the SCP and RCP instructions.

The state of pin enters the high-impedance state when the SCP instruction is executed.

The state of pin becomes “L” level when the RCP instruction is executed.

The output structure is an N-channel open-drain.

Note: Port C is also used as port D2. Accordingly, when using port C, set the output latch to “1” with

the SD instruction.

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Port K

Port K is a 1-bit I/O port.

s Input/output of port K

q Data input to port K

Set the output latch of specified port K to “1” with the OKA instruction. If the output latch is set

to “0,” “L” level is input.

The state of port K is transferred to register A when the IAK instruction is executed.

However, port K is 1 bit and A1, A2 and A3 are fixed to “0.”

q Data output from port K

The contents of register A is output to port K with the OKA instruction.

The output structure is an N-channel open-drain.

Note: Port K is also used as port D3. Accordingly, when using port K, set the output latch to “1” with

the SD instruction.

4501 Datasheet(PDF) 121 Page - Renesas Technology Corp