Table of Contents
Advertisement
6.2.7 Port 5
Port 5 is an 8-bit input/output port with output latch. P50 to P57 pins can be set to the input mode/output mode
bit-wise with the port mode register 5 (PM5). When P50 to P57 pins are used as input ports, an on-chip pull-up resistor
can be connected to them in 8-bit units with a pull-up resistor option register (PUO).
Port 5 can drive LEDs directly.
Alternate functions include address bus in external memory expansion mode.
RESET input sets port 5 to input mode.
Figure 6-13 shows a block diagram of port 5.
www.DataSheet4U.com
Figure 6-13. P50 to P57 Block Diagrams
WR
PUO
PUO5
RD
WR
PORT
Output Latch
(P50 to P57)
WR
PM
PM50 to PM57
PUO : Pull-up resistor option register
PM
: Port mode register
RD
: Port 5 read signal
WR : Port 5 write signal
CHAPTER 6 PORT FUNCTIONS
Selector
V
DD
P-ch
P50/A8 to
P57/A15
143
Advertisement
Table of Contents
