Aiwa CT-X2058 Service Manual page 10

1C DESCRIPTION
1C, TC9297F
Pin No. Pin Name
1 - 4 K1 - K 4
5 - 1 0 T 0 - T 5
11
COM1
12 COM 2
13
SO/COM3
14-48 S I ~ S35
4 9 -5 2
S36/OT3 - S39/OTO
53 G N D
54 O SC
55 V D D
56 R S T
57 C K
58 D A T A
59 C E
60
K0
I/O
K ey scan inputs. A maximum of 6x5=30 key data can be input with a matrix of key
I
scan outputs TO - T5. When "H " is applied to this pin, scanning of keys w ill start.
These pins incorporate pull-down resistors.
K ey scan timing outputs. Since a load resistor RO N is built into the N-ch to form a key
0
matrix, a diode is not necessary. In normal operation, these pins output "H ", and when
"H " is applied to key scan inputs K0 ~ K4, key scanning w ill start.
O
L C D common signal outputs. When 1/2 duty is set, matrixing of COM 1, 2 and
O
SO - S39 allows the display of up to 80 segments. When 1/3 duty is set, matrixing of
COM1-3 and S I ~ S39 allows display of up to 117 segments.In the 1/3 duty mode, the
O
SO pin is used as a COM 3 pin.
L C D segment signal outputs. When 1/2 duty is set, matrixing of COM 1, 2 and
o
SO - S39 allows display of up to 80 segments. When 1/3 duty is set, matrixing of
COM1-3 and S I - S39 allows display of up to 117 segments. S36 - S39 are commonly
0
used for L E D drivers. The L E D driver outputs become N-ch open drain outputs, and
the LED s can be directly indicated since they are driven by high current.
G N D
—
C and R which are attached externally form an oscillator.
The oscillation frequency is shown by the following formula:
fosc = 1.5/(C • R )[H z]
—
For example, when C = 0.01
fosc = ? 5 kHz.
Power supply input. Norm ally, a voltage V R S T - 5.5 V is applied. This pin is provided
with a power-on reset function: the system reset w ill function when power is turned on
or V D D is less than 3 V (standard).
Device system reset signal input. When R S T input is "L ", the oscillator w ill stop, all
internal data w ill be reset and the LC D output pins and key scan output pins w ill be
1
fixed at "H ". For normal operation, connect this pin to V D D , since the device
incorporates a power-on reset circuit.
Serial interface pins. The device communicates the display data, key input data and the
I
data which controls these with the controller. W hen the C E pin is "L ", data w ill not be
communicated. When it goes "H ", data w ill be communicated between the D A T A pin
I/O
and controller, synchronized with the clock signal input to the C K input pin. A ll these
I
pins have Schmitt input circuits.
K ey scan input. A maximum of 6x5=30 key data can be input with a matrix of key
I
scan outputs TO ~ T5. When "H " is applied to this pin, scanning of keys w ill start. This
pin incorporates a pull-down resistor.
14
Description
F and R = 30 k fl ,
¡x