Port 14 - NEC MuPD78F0132H User Manual

4.2.11 Port 14

Port 14 is a 2-bit I/O port with an output latch. Port 14 can be set to the input mode or output mode in 1-bit units
using port mode register 14 (PM14). When the P140 and P141 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 14 (PU14).
This port can also be used for external interrupt request input, buzzer output, and clock output.
RESET input sets port 14 to input mode.
Figure 4-20 shows a block diagram of port 14.
WR
PU
PU140, PU141
RD
WR
PORT
Output latch
(P140, P141)
WR
PM
PM140, PM141
PU14: Pull-up resistor option register 14
PM14: Port mode register 14
RD: Read signal
WR××: Write signal
CHAPTER 4 PORT FUNCTIONS
Figure 4-20. Block Diagram of P140 and P141
PU14
Alternate
function
PM14
Alternate
function
User's Manual U16899EJ2V0UD
EV
DD
P-ch
P140/PCL/INTP6,
P141/BUZ/INTP7
103