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Pin Definitions and Functions (cont'd)
Symbol
Pin
P-LCC-68
P1.7-P1.0 29-36
Semiconductor Group
Pin
Input (I)
P-MQFP-80
Output (O)
24-31
I/O
Function
Port 1
is an 8-bit bidirectional I/O port with
internal pullup resistors. Port 1 pins that
have 1's written to them are pulled high by
the internal pullup resistors, and in that
state can be used as inputs. As inputs,
port 1 pins being externally pulled low will
source current (I
characteristics) because of the internal
pullup resistors. The port is used for the
low-order address byte during program
verification. Port 1 also contains the
interrupt, timer, clock, capture and
compare pins that are used by various
options. The output latch corresponding to
a secondary function must be
programmed to a one (1) for that function
*
to operate (except when used for the
compare functions). The secondary
functions are assigned to the port 1 pins
as follows:
– INT3/CC0 (P1.0): interrupt 3 input/
compare 0 output/capture 0 input
– INT4/CC1 (P1.1): interrupt 4 input/
compare 1 output/capture 1 input
– INT5/CC2 (P1.2): interrupt 5 input/
compare 2 output/capture 2 input
– INT6/CC3 (P1.3): interrupt 6 input/
compare 3 output/capture 3 input
– INT2 (P1.4): interrupt 2 input
– T2EX (P1.5): timer 2 external reload
trigger input
– CLKOUT (P1.6): system clock output
– T2 (P1.7): counter 2 input
222
Device Specifications
in the DC
I L
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