Renesas 4514 User Manual

Page of 210
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.”