Datasheet
MAX7428/MAX7430/MAX7432A
Standard Definition Video Reconstruction
Filters and Buffers
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The broadcast sequence writes data to the control regis-
ters of all the devices on the bus at the same time. Write
data with the LSB first. The following is the command
sequence and timing diagram (Figure 9) for the broad-
cast transaction. No address sequence is required. Use
the broadcast command when there is only one device
on the bus.
Executing a software reset serves the same function as
a power-on reset and is achieved by transmitting all
data bits (eight or more) for the MAX7428, sixteen or
more ones for the MAX7430, or 24 or more ones for the
MAX7432A to that device register.
Composite Video Filtering
The MAX7428 is ideally suited for filtering composite
video signals. Program the SYNCIO as an output when
processing composite video signals. In the rare occa-
sion that an external sync pulse is needed to process
the composite video, program the SYNCIO as an input.
Broadcast Command Sequence:
T000
Data ≥ 8-bits (MAX7428)
Data ≥ 16-bits (MAX7430)
Data ≥ 24-bits (MAX7432A)
T111
Read Command Sequence:
T101
Prompts ≥ 8 (MAX7428)
Prompts ≥ 16 (MAX7430)
Prompts ≥ 24 (MAX7432A)
T111
ADDRESS: 0001
t
WAIT
t
INTWAIT
t
INT
t
T
t
1
t
1
t
1
t
T
t
1
t
1
t
1
t
0
t
0
t
0
t
0
LSB MSB
Figure 5. Initialization Timing Diagram
ADDRESS: 0001
t
WAIT
t
T
t
T
t
1
t
1
t
0
t
1
t
1
t
1
t
0
t
0
t
0
t
0
LSB MSB
Figure 6. Address Timing Diagram
DATA: 1***000
t
WAIT
t
T
t
1
t
0
t
1
t
T
t
1
t
1
t
1
t
0
t
0
t
0
t
0
LSB MSB
Figure 7. Write Timing Diagram
Software Reset Command Sequence:
T000
8 or more 1s (MAX7428)
16 or more 1s (MAX7430)
24 or more 1s (MAX7432A)
T111
OR
T010 Address = 4-bits T111
T001
8 or more 1s (MAX7428)
16 or more 1s (MAX7430)
24 or more 1s (MAX7432A)
T111