ML6461

24

MODE

PRESET1

PRESET0

CC

CNTR

A

0

0

XX

XXXXXXXX

B

0

1

XX

09080209

C

1

0

XX

1C080209

D

1

1

XX

11080209

X = don't care

Mode Description

Mode A: All register contents are programmed through serial interface.

Mode B: Master mode, CCIR656 rate, analog blanking.

Mode C: Slave mode, SAV and EAV codes, CCIR656 rate, digital blanking.

Mode D: Slave mode, external sync at start of line, Square pixel rate, analog blanking

Table 8. Preset Modes and Register Values

PRESET PIN CONTROL

The ML6461 can be controlled by a pair of preset mode

pins. These pins do not allow access to all of the

programmable features of the ML6461, but are intended to

provide a simpler interface for most applications. Refer to

Table 8 for preset modes.

SERIAL BUS OPERATION

The serial bus control in the ML6461 has two levels of

addressing: Device Addressing and Functional Addressing.

Device Addressing: Figures 15, 16, and 17 show the

physical waveforms generated in order to address the

ML6461. There are six basic parts of the waveform:

1. Start Indication: Clock Cycle 0

2. Device Address Shifted in: Clock Cycle 1 through 8

3. Device Address Strobed and Decoded: Clock Cycle 9

4. Function Address Shifted in: Clock Cycle 10 through 17

5. Function Address Strobed and Decoded: Clock Cycle 18

6. Data Shifted in 8 bits at a time, MSB first: Clock

Cycle 19 through 26

7. Data Shifted: Clock Cycle 27

8. Repeat strep 6 & 7 until all data is clocked in.

9. Stop indication: After Last Clock Cycle

(54 for CC, 54 for CNTR)

Note: data at SDATA is ignored at steps 3, 5, and 7.

Device & Function Addressing: Figures 15, 16, an17

show the register address procedure of the ML6461.

Device Address (8 bit)

1011 0100 (Hex = B4)

Function Address (8 bit)

Closed Caption Data Registers (CC): 0000 0000 (Hex = 00)

Control Registers (CNTR): 0000 0011 (Hex = 03)

Number of Data Bits

Closed Caption Data Registers (CC): 4 x 8 bits

Control Registers (CNTR): 4 x 8 bits

CONTROL REGISTER DEFAULT SETTINGS

At Power up, the ML6461 default settings are as follows:

•

Control Register is undefined when the serial

bus mode is enabled.

•

Chip is ready to process video

•

Preset Pins are available and if used will

configure the control register.

•

Must write logic “0” (zero) to A30 to get

video

To get black at power up will require logic “1” in A30.