¡ Semiconductor

ML9222

13/25

FEDL9222-02

FUNCTIONAL DESCRIPTION

Power-on Reset

When power is turned on, ML9222 is initialized by the internal power-on reset circuit.

The status of the internal circuit after initialization is as follows:

• The contents of the shift registers and latches are set to "0".

• The digital dimming duty cycle is set to "0".

• All segment outputs are set to Low level.

• All grid outputs are set to High level.

• All the ROW outputs are set to Low level.

• INT output is set to Low level.

Data Input and Output

Data input and output through the DATA I/O pin is valid only when the CS pin is set at a High

level.

The input data to DATA I/O pin is shifted into the shift register at the rising edge of the serial

clock. The data is automatically loaded to the latches when the CS pin is set at a Low level.

10-bit dimming data (D1 to D10) and 32-bit segment data (S1 to S32) are used for inputting of

dimming data and display data. To transfer these two data, the mode data (M0 to M2) must be

sent after each of these data succeddingly.

The output data from the DATA I/O pin is output from the shift register at the rising edge of the

serial clock.

ML9222 outputs 64-bit (8ch ¥ 8bits) A/D data (A11 to A88) and 37-bit key data (S11 to S55, R1,

Q11 to Q13, R2, Q21 to Q23, R3 and Q31 to Q33). To receive these data, the mode data (M0 to M2)

mast be sent first and then CS must be set once to Low level and set again to High level.

Then inputting serial clocks, these data are output from the DATA I/O pin.

When the CS pin is set at a Low level, the DATA I/O pin returns to an input pin.

To stop the keyscan, the only mode data (M0 to M2) must be sent. After the mode data transfer,

the key scanning is stopped immediately.

Mode Data

ML9222 has the seven function modes. The function mode is selected by the mode data (M0 to

M2). The relation between function mode and mode data (M0 to M2) is as follows:

FUNCTION MODE

OPERATING MODE

FUNCTION DATA

M0

M1

M2

000

0

Segment Data for GRID1-3 Input

100

1

Segment Data for GRID1 Input

010

2

Segment Data for GRID2 Input

110

3

Segment Data for GRID3 Input

001

4

Digital Dimming Data Input

101

5

Keyscan Stop

011

6

Switch Data Output

111

7

A/D Data Output