SAB88C166 Datasheet, PDF (5/58 Pages) Siemens Semiconductor Group – 16-Bit CMOS Single-Chip Microcontrollers with/without oscillator prescaler with 32 KByte Flash EPROM

SAB 88C166(W)
Pin Definitions and Functions
Symbol Pin
Input (I) Function
Number Output (O)
P4.0 –
P4.1
16 - 17 I/O
16
O
17
O
Port 4 is a 2-bit bidirectional I/O port. It is bit-wise
programmable for input or output via direction bits. For a pin
configured as input, the output driver is put into high-
impedance state.
In case of an external bus configuration, Port 4 can be used to
output the segment address lines:
P4.0
A16
Least Significant Segment Addr. Line
P4.1
A17
Most Significant Segment Addr. Line
XTAL1 20
I
XTAL2 19
O
XTAL1: Input to the oscillator amplifier and input to the
internal clock generator
XTAL2: Output of the oscillator amplifier circuit.
To clock the device from an external source, drive XTAL1,
while leaving XTAL2 unconnected. Minimum and maximum
high/low and rise/fall times specified in the AC Characteristics
must be observed.
BUSACT, 22
I
EBC1, 23
I
EBC0 24
I
V_PP
23
RSTIN 27
I
RSTOUT 28
O
External Bus Configuration selection inputs. These pins are
sampled during reset and select either the single chip mode
or one of the four external bus configurations:
BUSACT EBC1 EBC0 Mode/Bus Configuration
0
0
0
8-bit demultiplexed bus
0
0
1
8-bit multiplexed bus
0
1
0
16-bit muliplexed bus
0
1
1
16-bit demultiplexed bus
1
0
0
Single chip mode
1
0
1
Reserved.
1
1
0
Reserved.
1
1
1
Reserved.
After reset pin EBC1 accepts the programming voltage for the
Flash EPROM as an “alternate function”:
Flash EPROM Programming Voltage V_PP = 12 V.
Reset Input with Schmitt-Trigger characteristics. A low level at
this pin for a specified duration while the oscillator is running
resets the SAB 88C166(W). An internal pullup resistor permits
power-on reset using only a capacitor connected to V_SS.
Internal Reset Indication Output. This pin is set to a low level
when the part is executing either a hardware-, a software- or a
watchdog timer reset. RSTOUT remains low until the EINIT
(end of initialization) instruction is executed.
Semiconductor Group
4