Service manual

QT-CD250H/W
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IC51 VHiLC72121/-1: Electronic Tuning (LC72121) (1/2)
1 Xtal XIN Output Crystal oscillator connection.(4.5 MHz/7.2 MHz)
2 Ground VSSX Output Ground terminal for the crystal oscillation circuit system of LC72121.
3 Chip enable CE Output High level when inputting serial data (DI) to LC72121 or sending
serial data (DO).
4 Input data DI Input Input terminal for serial data that is transferred from the controller to
LC72121.
5 Clock CL Output Clock that synchronizes data when inputting serial data (DI) to
LC72121 or sending serial data (DO).
6 Output data DO Output Output terminal that sends data from LC72121 to the controller. The
output data is defined by serial data DOC0-DOC2.
7* Output port BO1 Output Output dedicated terminal.
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
8-10 Output port BO2-BO4 Output Output dedicated terminal.
Output state is defined by the serial data BO1-BO4.
Data 0: Open
Data 1: L
Time base signal (8 Hz) output is possible from BO1 terminal.
(When setting serial data TBC = 1.)
11 Input/output port IO1 Input/Output Terminal for both input and output.
Input and output are defined by serial data IDC1 and IOC2.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
12 IF counter IF IN Input Input frequency is 0.4-12 MHz.
Signal is transferred to the IF counter directly.
The result is sent from M5B of the IF counter through DO.
4 measuring times: 4, 8, 32, and 64 ms
13 Input/output port IO2 Input/Output Terminal for both input and output.
Input and output are defined by serial data IDC1 and IOC2.
Data 0: Input port
Data 1: Output port
When specified as the input port.
The input terminal state is transferred from the DO terminal to the
controller.
Input state "L": Data -> 0
Input state "H": Data -> 1
When specified as the output port.
Output state is defined by the serial data IO1 and IO2.
Data 0: Open
Data 1: L
When turning on the power or resetting, the terminal becomes the
input port.
14 Ground VSSD — Ground terminal for the digital system other than VSSA and VSSX of
LC72121.
Port Name
Terminal
Name
Pin No.
Input/Output
Function
FUNCTION TABLE OF IC
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.