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CHAPTER 5 PORT FUNCTIONS
User’s Manual U12697EJ3V0UM
5.2.5 Port 4
Port 4 is an 8-bit I/O port with output latch. The P40 to P47 pins can specify the input mode/output mode in 1-
bit units with the port 4 mode register. When the P40 to P47 pins are used as input ports, a pull-up resistor can be
connected in 8-bit units with bit 4 (PUO4) of the pull-up resistor option register.
Port 4 can drive LEDs directly.
Port 4 supports the address/data bus function in the external memory expansion mode as an alternate function.
RESET input sets port 4 to the input mode.
Figure 5-10 shows a block diagram of port 4.