C509-L_97 Datasheet, PDF (12/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Introduction
C509-L
1.2 Pin Definitions and Functions
This section describes all external signals of the C509-L with its function.
Table 1-1
Pin Definitions and Functions
Symbol
P1.0 - P1.7
*) I = Input
O = Output
Pin Number
9-6, 1,
100-98
9
8
7
6
1
100
99
98
I/O*) Function
I/O 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 _IL, in the DC
characteristics) because of the internal pullup resistors.
Port 1 can also be switched into a bidirectional mode, in
which CMOS levels are provided. In this bidirectional
mode, each port 1 pin can be programmed individually
as input or output.
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 pins of
port 1 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 CC4 Interrupt 2 input / compare 4 output /
capture 4 input
P1.5 T2EX
Timer 2 external reload trigger input
P1.6 CLKOUT System clock output
P1.7 T2
Counter 2 input
Semiconductor Group
1-5
1997-10-01