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CHAPTER 4 PORT FUNCTIONS
User’s Manual U15798EJ2V0UD
4.2.6 Port 7
Port 7 is a 4-bit I/O port with an output latch. The P70 to P73 pins can be set to input mode/output mode in 1-
bit units using port mode register 7 (PM7). In mask ROM versions use of a pull-up resistor can be set by mask option.
The P70 to P73 pins can drive LEDs directly.
RESET input sets port 7 to input mode.
Figure 4-13 shows a block diagram of port 7.
Figure 4-13. Block Diagram of P70 to P73
PM: Port mode register
RD: Port 7 read signal
WR: Port 7 write signal
RD
P70 to P73
WR
PORT
WR
PM
Output latch
(P70 to P73)
PM70 to PM73
Selector
V
DD0
Mask option resistor
Internal bus
Mask ROM version only
No pull-up resistor for
flash memory version
Содержание mPD780344 Series
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