
SAB 80C166/83C166
Semiconductor Group
6
P3.0 –
P3.15
80-92,
95-97
80
81
82
83
84
85
86
87
88
89
90
91
92
95
96
97
I/O
I/O
I
O
I
O
I
I
I
I
O
I/O
O
I/O
O
O
I
O
Port 3 is a 16-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.
The following Port 3 pins also serve for alternate functions:
P3.0
T0IN
CAPCOM Timer T0 Count Input
P3.1
T6OUT GPT2 Timer T6 Toggle Latch Output
P3.2
CAPIN
GPT2 Register CAPREL Capture Input
P3.3
T3OUT GPT1 Timer T3 Toggle Latch Output
P3.4
T3EUD GPT1 Timer T3 Ext.Up/Down Ctrl.Input
P3.5
T4IN
GPT1 Timer T4 Input for
Count/Gate/Reload/Capture
P3.6
T3IN
GPT1 Timer T3 Count/Gate Input
P3.7
T2IN
GPT1 Timer T2 Input for
Count/Gate/Reload/Capture
P3.8
TxD1
ASC1 Clock/Data Output (Asyn./Syn.)
P3.9
RxD1
ASC1 Data Input (Asyn.) or I/O (Syn.)
P3.10
T
×
D0
ASC0 Clock/Data Output (Asyn./Syn.)
P3.11
R
×
D0
ASC0 Data Input (Asyn.) or I/O (Syn.)
P3.12
BHE
Ext. Memory High Byte Enable Signal
P3.13
WR
External Memory Write Strobe
P3.14
READY Ready Signal Input
P3.15
CLKOUTSystem Clock Output (=CPU Clock)
P0.0 –
P0.15
98 – 5
8 – 15
I/O
Port 0 is a 16-bit bidirectional IO 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 0 serves as the
address (A) and address/data (AD) bus in multiplexed bus
modes and as the data (D) bus in demultiplexed bus modes.
Demultiplexed bus modes:
Data Path Width:
8-bit
P0.0 – P0.7:
D0 – D7
P0.8 – P0.15:
output!
Multiplexed bus modes:
Data Path Width:
8-bit
P0.0 – P0.7:
AD0 – AD7
P0.8 – P0.15:
A8 - A15
16-bit
D0 - D7
D8 - D15
16-bit
AD0 - AD7
AD8 - AD15
V
AREF
V
AGND
54
-
Reference voltage for the A/D converter.
55
-
Reference ground for the A/D converter.
Pin Definitions and Functions
(cont’d)
Symbol
Pin
Number
Input
Output
Function