CHAPTER 4 PORT FUNCTIONS
User’s Manual U17446EJ3V1UD
62
Figure 4-13. Block Diagram of P121 and P122
P121/X1,
P122/X2
RD
WR
PORT
WR
PM
Output latch
(P121, P122)
PM121, PM122
PM12
Internal bus
Selector
P12
PM12: Port mode register 12
P12:
Port register 12
RD:
Read signal
WR
××
: Write signal
4.2.6 Port
13
This is a 1-bit output-only port.
Figure 4-14 shows the block diagram of port 13.
Figure 4-14. Block Diagram of P130
RD
Output latch
(P130)
WR
PORT
P130
Internal bus
P13
P13:
Port register 13
RD:
Read signal
WR
××
: Write signal
Remark
When a reset is input, P130 outputs a low level. If P130 outputs a high level immediately after
reset is released, the output signal of P130 can be used as a dummy CPU reset signal.
Содержание 78K0S/KB1+
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