SAB80C515A-5 SIEMENS [Siemens Semiconductor Group], SAB80C515A-5 Datasheet - Page 58

• Manufacturer Part Number: SAB80C515A-5
• Description: 8-Bit CMOS Single-Chip Microcontroller Family
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Pin Definitions and Functions
Symbol
P4.0-P4.7 1-3, 5-9
PE/SWD
RESET
V
V
Semiconductor Group
AGND
AREF1
Pin
P-LCC-68
4
10
11
12
Pin
P-MQFP-80
72-74,
76-80
75
1
3
4
Input (I)
Output (O)
I/O
I
I
6-6
Function
Port 4
is an 8-bit bidirectional I/O port with internal
pull-up resistors. Port 4 pins that have 1’s writ-
ten to them are pulled high by the internal pull-
up resistors, and in that state can be used as
inputs. As inputs, port 4 pins being externally
pulled low will source current ( I
characteristics) because of the internal pull-up
resistors.
P4 also contains the external A/D converter
control pin. The output latch corresponding to
a secondary function must be programmed to
a one (1) for that function to operate. The sec-
ondary function assigned to port 6:
– ADST(P4.0): external A/D converter start
Power saving mode enable/Start Watch-
dog Timer
A low level on this pin allows the software to
enter the power down, idle and slow down
mode. In case the low level is also seen during
reset, the watchdog timer function is off on de-
fault.
Use of the software controlled power saving
modes is blocked, when this pin is held on
high level. A high level during reset performs
an automatic start of the watchdog timer im-
mediately after reset.
When left unconnected this pin is pulled high
by a weak internal pull-up resistor.
Reset pin
A low level on this pin for the duration of two
machine cycles while the oscillator is running
resets the SAB 80C515A. A small internal
pullup resistor permits power-on reset using
only a capacitor connected to V
Reference voltage for the A/D converter
Reference ground for the A/D converter
SAB 80C515A/83C515A-5
pin
SS
IL
, in the DC