Renesas 4514 - Manual (Page 105)

2-2
APPLICATION
2.1 I/O pins
4513/4514 Group User’s Manual
2.1 I/O pins
The 4513/4514 Group has the twenty-eight I/O pins (eighteen I/O pins for 4513 Group), three input pins.
(Ports P2
0 –P2 2 , P3 0 , P3 1 , D 6 and D 7 are also used as serial I/O pins S CK , S OUT , S IN , and INT0, INT1,
CNTR0 and CNTR1 pins, respectively).
This section describes each port I/O function, related registers, application example using each port function
and notes.
2.1.1 I/O ports
(1) Port P0
Port P0 is a 4-bit I/O port.
Port P0 has the key-on wakeup function which turns ON/OFF with register K0 and pull-up transistor
which turns ON/OFF with register PU0.
■ Input/output of port P0
●
●
Data input to port P0
Set the output latch of specified port P0i (i=0 to 3) to “1” with the OP0A instruction. If the output
latch is set to “0,” “L” level is input.
The state of port P0 is transferred to register A when the IAP0 instruction is executed.
Data output from port P0
The contents of register A is output to port P0 with the OP0A instruction.
The output structure is an N-channel open-drain.
(2) Port P1
Port P1 is a 4-bit I/O port.
Port P1 has the key-on wakeup function which turns ON/OFF with register K0 and pull-up transistor
which turns ON/OFF with register PU0.
■ Input/output of port P1
●
●
Data input to port P1
Set the output latch of specified port P1i (i=0 to 3) to “1” with the OP1A instruction. If the output
latch is set to “0,” “L” level is input.
The state of port P1 is transferred to register A when the IAP1 instruction is executed.
Data output from port P1
The contents of register A is output to port P1 with the OP1A instruction.
The output structure is an N-channel open-drain.
(3) Port P2
Port P2 is a 3-bit input port.
■ Input of port P2
● Data input to port P2
The state of port P2 is transferred to register A when the IAP2 instruction is executed. However,
port P2 is 3 bits and A
3 is fixed to “0.”