Port 3 (p3) – Maxim Integrated High-Speed Microcontroller Users Guide: Network Microcontroller Supplement User Manual
Page 60
High-Speed Microcontroller User’s
Guide: Network Microcontroller
Supplement
60
Port 3 (P3)
7
6
5
4
3
2
1
0
SFR B0h
P3.7
RD
P3.6
WR
P3.5
T1
P3.4
T0
P3.3
INT1
P3.2
INT0
P3.1
TXD0
P3.0
RXD0
RW-1
RW-1
RW-1
RW-1
RW-1
RW-1
RW-1
RW-1
R = Unrestricted read, W = Unrestricted write, -n = Value after reset
P3.7–0
Bits 7–0
RD
Bit 7
WR
Bit 6
T1
Bit 5
T0
Bit 4
INT1
Bit 3
INT0
Bit 2
TXDO
Bit 1
RXDO
Bit 0
General-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 as follows. Several other SFRs control each of the functions. The
associated port 1 latch bit must contain a logic 1 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 memo-
ry device.
External data memory write strobe. This pin provides an active-low write strobe to an external mem-
ory device
Timer/counter external input. A 1-to-0 transition on this pin increments timer 1.
Counter external input. A 1-to-0 transition on this pin increments timer 0.
External interrupt 1. A falling edge/low level on this pin causes an external interrupt 1 if enabled.
External interrupt 0. A falling edge/low level on this pin causes an external interrupt 0 if enabled.
Serial port 0 transmit. This pin transmits the serial port 0 data in serial port modes 1, 2, and 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, and 3 and emits
the synchronizing clock in serial port mode 0.
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