NEC PD78078 用户手册

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CHAPTER 6 PORT FUNCTIONS

6.2.9 Port 7

This is a 3-bit input/output port with output latches. Input mode/output mode can be specified in 1-bit units with

a port mode register 7 (PM7). When pins P70 to P72 are used as input port pins, an on-chip pull-up resistor can

be connected in 3-bit units with a pull-up resistor option register L (PUOL).

Dual-functions include serial interface channel 2 data input/output and clock input/output.

RESET input sets the input mode.

Port 7 block diagrams are shown in Figures 6-15 and 6-16.

Caution When used as a serial interface, set the input/output and output latch according to its functions.

For the setting method, refer to Table 20-2. Serial Interface Channel 2 Operating Mode Setting.

Figure 6-15. Block Diagram of P70

PUO : Pull-up resistor option register

: Port mode register

: Port 7 read signal

WR : Port 7 write signal

P-ch

PORT

PUO

Selector

PUO7

Output Latch

(P70)

PM70

Internal bus

P70/SI2/RxD