MAX7469 Datasheet, PDF (13/17 Pages) Maxim Integrated Products – HDTV Continuously Variable Anti-Aliasing Filters

HDTV Continuously Variable
Anti-Aliasing Filters
write sequence must be repeated. Figures 6 and 7
show examples of write sequences.
Read Cycle
In read mode (R/W = 1), the MAX7469/MAX7470 write
the contents of the control/status or frequency registers
to the bus. When the command byte indicates a read
operation of either the control/status or the frequency
register, the serial interface expects an Sr condition to
follow the command byte. After sending an Sr, the mas-
ter sends the MAX7469/MAX7470 slave address byte
followed by a R/W bit (set to 1 to indicate a read). The
slave device (MAX7469/MAX7470) generates an ACK
for the second address word and immediately after the
ACK clock pulse, the direction of data flow reverses.
The slave (MAX7469/MAX7470) then transmits 1 byte of
data containing the value of the register that was
SCL
SDA
SDA
DIRECTION
1
0
0
1
0
A1
A0 R/W
ACK 0
0
0
1
0
0
1
0 ACK
C7 C6 C5 C4 C3 C2 C1 C0
IN TO MAX7469/MAX7470
OUT
IN
OUT
START
SCL (CONT)
SDA (CONT)
F7 F6 F5 F4 F3 F2 F1 F0 ACK
SDA
IN
DIRECTION
COMMAND BYTE C7–C0 IS 0010010.
Figure 6. Write Sequence to Update the Frequency Register
OUT
IN
STOP
SCL
SDA
SDA
DIRECTION
1
0
0
1
0
A1 A0 R/W
ACK 0
0
0
0
0
0
0
0 ACK
C7
C6
C5 C4
C3
C2 C1
C0
IN TO MAX7469/MAX7470
OUT
IN
OUT
IN
START
THE COMMAND BYTE IS FOR POWER-DOWN.
STOP
Figure 7. Write Sequence for a Command Byte
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