C515A_9708 Datasheet, PDF (12/182 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Introduction
C515A
Table 1-1
Pin Definitions and Functions (cont’d)
Symbol
P1.0 - P1.7
V_CC
V_SS
*) I = Input
O = Output
Pin Number
(P-MQFP-80)
31-24
31
30
29
28
27
26
25
24
32, 33
34, 35
I/O*) Function
I/O Port 1
is an 8-bit quasi-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 _IL, in the DC
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 :
P1.0 / INT3 / CC0 Interrupt 3 input /
compare 0 output /
capture 0 input
P1.1 / INT4 / CC1 Interrupt 4 input /
compare 1 output /
capture 1 input
P1.2 / INT5 / CC2 Interrupt 5 input /
compare 2 output /
capture 2 input
P1.3 / INT6 / CC3 Interrupt 6 input /
compare 3 output /
capture 3 input
P1.4 / INT2
Interrupt 2 input
P1.5 / T2EX
Timer 2 external reload /
trigger input
P1.6 / CLKOUT
System clock output
P1.7 / T2
Counter 2 input
– Supply Voltage
during normal, idle, and power down mode.
– Ground (0V)
during normal, idle, and power down operation.
Semiconductor Group
1-7
1997-08-01