C501_1 Datasheet, PDF (16/121 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller

Introduction
C501
Table 1-1
Pin Definitions and Functions (cont’d)
Symbol
Pin Number
I/O*) Function
P-LCC-44 P-DIP-40 P-MQFP-44
P0.0 – P0.7 43–36 39–32 37–30
I/O Port 0
is an 8-bit open-drain bidirectional I/O
port. Port 0 pins that have 1s written to
them float, and in that state can be used
as high-impedance inputs. Port 0 is also
the multiplexed low-order address and
data bus during accesses to external
program or data memory. In this
application it uses strong internal pull-up
resistors when issuing 1s.
Port 0 also outputs the code bytes during
program verification in the C501-1R and
C501-1E. External pull-up resistors are
required during program verification.
V_SS
V_CC
N.C.
22
20
44
40
1, 12,
–
23, 34
16
38
6, 17,
28, 39
– Circuit ground potential
– Supply terminal for all operating modes
– No connection
*) I = Input
O = Output
Semiconductor Group
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