UPD78F0411GA-GAM-AX Datasheet, PDF (85/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 4 PORT FUNCTIONS
4.2.3 Port 3
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
using port mode register 3 (PM3). When the P31 to P34 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).
This port can also be used for external interrupt request input, timer I/O, manchester code generator output, real-
time counter output, and buzzer output.
Reset signal generation sets port 3 to input mode.
Figures 4-5 and 4-6 show block diagrams of port 3.
WRPU
RD
Figure 4-5. Block Diagram of P31, P33, P34
VDD
PU3
PU31, PU33, PU34
Alternate
function
P-ch
WRPORT
WRPM
P3
Output latch
(P31, P33, P34)
PM3
PM31, PM33, PM34
Alternate
function
P31/TOH1/INTP3,
P33/TI000/RTCDIV/RTCCL/BUZ/INTP2,
P34/TI52/TI010/TO00/RTC1HZ/INTP1
P3: Port register 3
PU3: Pull-up resistor option register 3
PM3: Port mode register 3
RD: Read signal
WR××: Write signal
User’s Manual U18698EJ1V0UD
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