16 port 1 (p1), Clock control (ckcon) – Maxim Integrated High-Speed Microcontroller User Manual
Page 32
High-Speed Microcontroller User’s Guide
Rev: 062210
32 of 176
4.2.16
Port 1 (P1)
7 6 5 4 3 2 1 0
SFR 90h
P1.7
INT5
P1.6
INT4
P1.5
INT3
P1.4
INT2
P1.3
TXD1
P1.2
RXD1
P1.1
T2EX
P1.0
T2
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
P1.7–P1.0
Bits 7–0
General-Purpose I/O Port 1. This register functions as a general purpose I/O port. In
addition, all the pins have an alternative function listed below. P1.2-7 contain functions
that are new to the 80C32 architecture. The Timer 2 functions on pins P1.1-0 are
available on the 80C32, but not the 80C31. 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.
INT5
Bit 7
External Interrupt 5. A falling edge on this pin will cause an external interrupt 5 if
enabled.
INT4
Bit 6
External Interrupt 4. A rising edge on this pin will cause an external interrupt 4 if
enabled.
INT3
Bit 5
External Interrupt 3. A falling edge on this pin will cause an external interrupt 3 if
enabled.
INT2
Bit 4
External Interrupt 2. A rising edge on this pin will cause an external interrupt 2 if
enabled.
TXD1
Bit 3
Serial Port 1 Transmit. This pin transmits the serial port 1 data in serial port modes 1,
2, 3 and emits the synchronizing clock in serial port mode 0.
RXD1
Bit 2
Serial Port 1 Receive. This pin receives the serial port 1 data in serial port modes 1, 2,
3 and is a bi-directional data transfer pin in serial port mode 0.
T2EX
Bit 1
Timer 2 Capture/Reload Trigger. A 1-to-0 transition on this pin will cause the value
in the
registers to be transferred into the capture registers if
enabled by EXEN2 (
.3). When in auto-reload mode, a 1-to-0 transition on this
pin will reload the timer 2 registers with the value in RCAP2L and RCAP2H if enabled
by EXEN2 (
T2
Bit 0
Timer 2 External Input. A 1-to-0 transition on this pin will cause timer 2 increment or
decrement depending on the timer configuration.