C501G-1E SIEMENS [Siemens Semiconductor Group], C501G-1E Datasheet - Page 13

• Manufacturer Part Number: C501G-1E
• Description: 8-Bit Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Table 1-1
Pin Definitions and Functions (cont’d)
Symbol
P3.0 – P3.7 11,
Semiconductor Group
*) I
O = Output
= Input
P-LCC-44 P-DIP-40 P-MQFP-44
13–19
11
13
14
15
16
17
18
19
Pin Number
10–17
10
11
12
13
14
15
16
17
5, 7–13
5
7
8
9
10
11
12
13
1-7
I/O*) Function
I/O
Port 3
is a quasi-bidirectional I/O port with
internal pull-up resistors. Port 3 pins that
have 1s written to them are pulled high by
the internal pull-up resistors, and in that
state they can be used as inputs. As
inputs, port 3 pins being externally pulled
low will source current (
characteristics) because of the internal
pull-up resistors. Port 3 also contains the
interrupt, timer, serial port 0 and external
memory strobe pins which 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:
P3.0 R D
P3.1 T D
P3.2 INT0
P3.3 INT1
P3.4 T0
P3.5 T1
P3.6 WR
P3.7 RD
receiver data input (asyn-
chronous) or data input
output (synchronous) of
serial interface 0
transmitter data output
(asynchronous) or clock
output (synchronous) of
the serial interface 0
interrupt 0 input/timer 0
gate control
interrupt 1 input/timer 1
gate control
counter 0 input
counter 1 input
the write control signal lat-
ches the data byte from
port 0 into the external
data memory
the read control signal
enables the external data
memory to port 0
I
IL
Introduction
, in the DC
C501