upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 75

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

4.2.4 Port 3
using port mode register 3 (PM3). When the P30 to P33 pins are used as an input port, use of an on-chip pull-up
resistor can be specified in 1-bit units by pull-up resistor option register 3 (PU3).
Port 3 is a 4-bit I/O port with an output latch. Port 3 can be set to the input mode or output mode in 1-bit units
This port can also be used for external interrupt request input.
RESET input sets port 3 to input mode.
Figure 4-11 shows a block diagram of port 3.
PU3:
PM3:
RD:
WR××: Write signal
WR
WR
WR
RD
PORT
PU
PM
Pull-up resistor option register 3
Port mode register 3
Read signal
PM30 to PM33
PU30 to PU33
(P30 to P33)
Output latch
Alternate
function
PM3
PU3
Figure 4-11. Block Diagram of P30 to P33
CHAPTER 4 PORT FUNCTIONS
User’s Manual U16846EJ3V0UD
V
DD
P-ch
P30/INTP1 to
P33/INTP4
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