CHAPTER 5 PORT FUNCTIONS
Preliminary User’s Manual U17260EJ3V1UD
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5.2.11 Port 14
Port 14 is a 6-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, clock output, serial interface data I/O,
clock I/O, busy input, and strobe output.
Reset signal generation sets port 14 to input mode.
Figures 5-25 shows a block diagram of port 14.
Figure 5-25. Block Diagram of P140 and P141
P140/PCL/INTP6,
P141/BUZ/INTP7
WR
PU
RD
WR
PORT
WR
PM
PU140, PU141
Alternate
function
Output latch
(P140, P141)
PM140, PM141
Alternate
function
EV
DD
P-ch
Selector
Internal bus
PU14
PM14
P14
P14:
Port register 14
PU14:
Pull-up resistor option register 14
PM14: Port mode register 14
RD: Read
signal
WR
××
: Write
signal