DS80C320-ECD DALLAS [Dallas Semiconductor], DS80C320-ECD Datasheet - Page 36

• Manufacturer Part Number: DS80C320-ECD
• Description: High-Speed Microcontroller User Guide
• Manufacturer: DALLAS [Dallas Semiconductor]

Port 3 (P3)
SFR B0h
P3.7-0
Bits 7-0
Bit 7
Bit 6
T1
Bit 5
T0
Bit 4
Bit 3
Bit 2
TXD0
Bit 1
RXD0
Bit 0
RD
INT1
INT0
WR
R=Unrestricted Read, W=Unrestricted Write, -n=Value after Reset
RW-1
P3.7
RD
7
Purpose I/O Port 3. This register functions as a general purpose I/O port. In
addition, all the pins have an alternative function listed below. Each of the
functions is controlled by several other SFRs. The associated Port 1 latch bit
must contain a logic one before the pin can be used in its alternate function
capacity.
External Data Memory Read Strobe. This pin provides an active low read
strobe to an external memory device.
External Data Memory Write Strobe. This pin provides an active low write
strobe to an external memory device.
Timer/Counter External Input. A 1 to 0 transition on this pin will increment
Timer 1.
Counter External Input. A 1 to 0 transition on this pin will increment Timer 0.
External Interrupt 1. A falling edge/low level on this pin will cause an
external interrupt 1 if enabled.
External Interrupt 0. A falling edge/low level on this pin will cause an
external interrupt 0 if enabled.
Serial Port 0 Transmit. This pin transmits the serial port 0 data in serial port
modes 1, 2, 3 and emits the synchronizing clock in serial port mode 0.
Serial Port 0 Receive. This pin receives the serial port 0 data in serial port
modes 1, 2, 3 and is a bi-directional data transfer pin in serial port mode 0.
RW-1
P3.6
WR
6
RW-1
P3.5
T1
5
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RW-1
P3.4
T0
4
RW-1
INT
P3.3
3
1
High-Speed Microcontroller User’s Guide
RW-1
INT
P3.2
2
0
TXD0
RW-1
P3.1
1
RXD0
RW-1
P3.0
0