SAB80C515A-5 Datasheet, PDF (85/108 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller Family

SAB 80C515A/83C515A-5
I/O Ports
The SAB 80C515A has six 8-bit I/O ports and one input port. Port 0 is an open-drain
bidirectional I/O port, while ports 1 to 5 are quasi-bidirectional I/O ports with internal pull-up
resistors. That means, when configured as inputs, ports 1 to 5 will be pulled high and will source
current when externally pulled low. Port 0 will float when configured as input.
Port 0 and port 2 can be used to expand the program and data memory externally. During an
access to external memory, port 0 emits the low-order address byte and reads/writes the data
byte, while port 2 emits the high-order address byte. In this function, port 0 is not an open-drain
port, but uses a strong internal pull-up FET. Ports 1, 3 and 4 are provided for several alternate
functions, as listed below:
Port
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P3.0
P3.1
P3.2
P3.3
P3.4
P3.5
P3.6
P3.7
P4.0
Symbol
INT3/CC0
INT4/CC1
INT5/CC2
INT6/CC3
INT2
T2EX
CLKOUT
T2
RxD
TxD
INT0
INT1
T0
T1
WR
RD
ADST
Function
External interrupt 3 input, compare 0 output, capture 0 input
External interrupt 4 input, compare 1 output, capture 1 input
External interrupt 5 input, compare 2 output, capture 2 input
External interrupt 6 input, compare 3 output, capture 3 input
External interrupt 2 input
Timer 2 external reload trigger input
System clock output
Timer 2 external count or gate input
Serial port’s receiver data input (asynchronous) or
data input /output (synchronous)
Serial port’s transmitter data output (asynchronous) or
clock output (synchronous)
External interrupt 0 input, timer 0 gate control
External interrupt 1 input, timer 1 gate control
Timer 0 external counter input
Timer 1 external counter input
External data memory write strobe
External data memory read strobe
A/D Converter, external start of conversion
The SAB 80C515A has one dual-purpose input port. The ANx lines of port 6 in the SAB 80C515
can individually be used as analog or digital inputs. Reading the special function register P6
allows the user to input the digital values currently applied to the port pins. It is not necessary
to select these modes by software; the voltages applied at port 6 pins can be converted to
digital values using the A/D converter and at the same time the pins can be read via SFR P6.
It must be noted, however, that the results in port P6 bits will be indeterminate if the levels at
the corresponding pins are not within their V_IL/V_IH specifications. Furthermore, it is not possible
to use port P6 as an output port. Special function register P6 is located at address 0DB_H.
In Hardware Power Down Mode the port pins and several control lines enter a floating state.
For more details see the section about Hardware Power Down Mode.
Semiconductor Group
6-33