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CHAPTER 5 PORT FUNCTIONS
5.2.3 Port 2
Port 2 is an 8-bit output only port with output latch. P20 to P27 pins go into a high-impedance state when the ENn
of port mode control register (PMC) is set to 0 and the port mode register 2 (PM2) is set to 1.
Alternate functions include meter control PWM output.
RESET input sets port 2 to high-impedance state.
Figure 5-4 shows a block diagram of port 2.
Figure 5-4. P20 to P27 Block Diagram
PM : Port mode register
RD : Port 2 read signal
WR : Port 2 write signal
Caution
When PM2 is set to 0, read operation is enabled. When PM2 is set to 1, read operation is disabled.
Remark
n = 1, 2
P20/SM11 to P23/SM14
P24/SM21 to P27/SM24
WR
PORT
WR
PM
Output latch
(P20 to P27)
Selector
Decoder
PM20 to PM27
2
Alternate
functions
Internal bus
RD
DIRn1 DIRn0
MODn ENn
Содержание mPD780973 Series
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