SAB80C517A-N18 Siemens Semiconductor Group, SAB80C517A-N18 Datasheet - Page 14

• Manufacturer Part Number: SAB80C517A-N18
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: Siemens Semiconductor Group

Pin Definitions and Functions (cont’d)
Symbol
HWPD
P5.7 - P5.0 61 - 68
OWE
*
Semiconductor Group
I = Input
O = Output
P-LCC-84
60
69
Pin Number
P-MQFP-100-2
36
37 - 44
45
I/O
I
I/O
I
I/O
13
*)
Function
Hardware Power Down
A low level on this pin for the duration of
one machine cycle while the oscillator is
running resets the SAB 80C517A. A low
level for a longer period will force the part to
Power Down Mode with the pins floating.
(see table 7)
Port 5
is a bidirectional I/O port with internal pull-
up resistors. Port 5 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 5
pins being externally pulled low will source
current (I
because of the internal pull-up resistors.
This port also serves the alternate function
"Concurrent Compare" and "Set/Reset
Compare". The secondary functions are
assigned to the port 5 pins as follows:
– CCM0 to CCM7 (P5.0 to P5.7):
Oscillator Watchdog Enable
A high level on this pin enables the
oscillator watchdog. When left
unconnected this pin is pulled high by a
weak internal pull-up resistor. When held at
low level the oscillator watchdog function is
off.
concurrent compare or Set/Reset
IL
SAB 80C517A/83C517A-5
, in the DC characteristics)
1994-05-01