SAB80C517 Datasheet, PDF (10/61 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller

SAB 80C517/80C537
Pin Definitions and Functions (cont’d)
Symbol
Pin Number
I/O ^*) Function
P-LCC-84 P-MQFP-100-2
P1.7 - P1.0 29 - 36
98 - 100,
1, 6 - 9
* _{I = Input}
O = Output
I/O Port 1
is a bidirectional I/O port with internal
pull-up resistors. Port 1 pins that have
1 s written to them are pulled high by
the internal pull-up resistors, and in that
state can be used as inputs. As inputs,
port 1 pins being externally pulled low
will source current (I_IL, in the DC
characteristics) because of the internal
pull-up resistors. It is used for the low
order address byte during program
verifi-cation. It also contains the
interrupt, timer, clock, capture and
compare pins that are used by various
options. The output latch 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/CC4 (P1.4): interrupt 2 input /
compare 4 output /capture 4 input
– T2EX (P1.5): timer 2 external reload
trigger input
– CLKOUT (P1.6): system clock
output
– T2 (P1.7): counter 2 input
Semiconductor Group
9