¡ Semiconductor

ML9261/62

13/16

FUNCTIONAL DESCRIPTION

Display Data Reset

When the power is turned on, the shift register outputs (PO1 to PO60) and register outputs (O1

to O60) are indeterminate. Consequently the display of a VFD tube may flickers because

unnecessary driver outputs go high. To prevent such flicker, it is required to perform the

following operations.

1. Turn on the logic power supply while the CL input is kept low.

2. Set the LS input high.

3. Switch the CLK input from a low level to a high level at least once.

By performing the above operations, the shift register outputs (PO1 to PO60) and register outputs

(O1 to O60) all are set low.

4. Enter display data.

5. Set the CL input high.

Data Transfer

Write display data by using a serial transfer.

Serial data is input in the shift register at the rising edge of a CLK input pulse.

When the LS input rises, display data is written in the latch.

Driver Output Control

1. To turn on or off driver outputs by using display data transfered into the shift register, set the

CL input high and set the CHG input low.

2. To set all the driver outputs low, set the CL input low.

3. To set all the driver outputs high, set the CL input and CHG input high at a time.