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CHAPTER 4 PORT FUNCTIONS
Preliminary User’s Manual U16035EJ1V0UM
Figure 4-5. Block Diagram of P21 and P24
RD
P21/SO30,
P24/TxD0
P-ch
WR
PU
WR
PORT
WR
PM
PU21, PU24
Output latch
(P21, P24)
PM21, PM24
Selector
V
DD0
Internal bus
Alternate
function
PU:
Pull-up resistor option register
PM: Port mode register
RD: Port 2 read signal
WR: Port 2 write signal