
CHAPTER 4 PORT FUNCTIONS
User’s Manual U15905EJ2V1UD
137
(3) Block diagram
Figure 4-18. Block Diagram of P90 and P91
Internal
bus
WRPMC
RD
Address
A0, A1 output
Output buffer
off signal
WRPORT
P90/A0,
P91/A1
PMC9n
Output latch
(P9n)
Selector
WRPM
PM9n
WRPU
PU9n
PMC9
P9
PM9
PU9
EVDD
P-ch
Remarks 1. P9:
Port register 9
PM9:
Port mode register 9
PMC9: Port mode control register 9
PU9:
Pull-up resistor option register 9
Output buffer off signal: Signal that is active in the IDLE/STOP mode or during bus hold
2. n = 0 or 1