
CHAPTER 4 PORT FUNCTIONS
User’s Manual U17854EJ9V0UD
99
Figure 4-5. Block Diagram of P03 and P04
P03/SI10/RxD1/SDA10,
P04/SCK10/SCL10
WRPU
RD
WRPORT
PU03, PU04
EVDD
P-ch
PU0
P0
WRPM
PM0
POM03, POM04
POM0
WRPOM
PM03, PM04
CMOS
TTL
PIM0
PIM03, PIM04
WRPIM
Alternate
function
Output latch
(P03, P04)
Alternate
function
Selector
Internal
bus
P0:
Port register 0
PU0:
Pull-up resistor option register 0
PM0:
Port mode register 0
PIM0:
Port input mode register 0
POM0: Port output mode register 0
RD:
Read signal
WR
××: Write signal