8
1.3.2
Pin Functions
Table 1.2 outlines the pin functions.
Table 1.2
Pin Functions
Pin No.
Type
Symbol
TFP-80F
TFP-80C
FP-80B
I/O
Name and Functions
Power
source pins
V
CC
7, 26
9, 28
Input
Power supply: All V
CC
pins should be
connected to the system power supply
(+5 V)
V
SS
3, 25
5, 27
Input
Ground: All V
SS
pins should be
connected to the system power supply
(0 V)
AV
CC
75
77
Input
Analog power supply: This is the power
supply pin for the A/D converter. When
the A/D converter is not used, connect
this pin to the system power supply
(+5 V).
AV
SS
80
2
Input
Analog ground: This is the A/D
converter ground pin. It should be
connected to the system power supply
(0 V).
VT
ref
74
76
Input
DTMF generator reference level: This
is a power supply pin for the reference
level for DTMF.
Clock pins
OSC
1
5
7
Input
System clock: These pins connect to a
crystal or ceramic oscillator, or can be
OSC
2
4
6
Output
used to input an external clock. See
section 4, Clock Pulse Generators, for a
typical connection diagram.
X
1
1
3
Input
Subclock: These pins connect to a
32.768-kHz crystal oscillator. See section
X
2
2
4
Output
4, Clock Pulse Generators, for a typical
connection diagram.
System
control
RES
8
10
Input
Reset: When this pin is driven low, the
chip is reset
TEST
6
8
Input
Test: This is a test pin, not for use in
applica-tion systems. It should be
connected to V
SS
.