SAB80C537 INFINEON [Infineon Technologies AG], SAB80C537 Datasheet - Page 9

• Manufacturer Part Number: SAB80C537
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: INFINEON [Infineon Technologies AG]

Pin Definitions and Functions (cont’d)
Symbol
P3.0 - P3.7
*
Semiconductor Group
I = Input
O = Output
P-LCC-84
21 - 28
Pin Number
P-MQFP-100-2
90 - 97
8
I/O
I/O
*)
Function
Port 3
is a bidirectional I/O port with internal
pull-up resistors. Port 3 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 3 pins being externally pulled low
will source current (I
characteristics) because of the internal
pull-up resistors. Port 3 also contains
the interrupt, timer, serial port 0 and
external memory strobe 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.
The secondary functions are assigned
to the pins of port 3, as follows:
– R
– T
– INT0 (P3.2): interrupt 0 input/timer 0
– INT1 (P3.3): interrupt 1 input/timer 1
– T0 (P3.4): counter 0 input
– T1 (P3.5): counter 1 input
– WR (P3.6): the write control signal
– RD (P3.7): the read control signal
(asynchronous) or data input/output
(synchronous) of serial interface
output (asynchronous) or clock
output (synchronous) of serial
interface 0
gate control
gate control
latches the data byte from port 0 into
the external data memory
enables the external data
memory to port 0
D0 (P3.1): transmitter data
D0 (P3.0): receiver data input
SAB 80C517/80C537
IL,
in the DC