MAX9526 Maxim Integrated Products, MAX9526 Datasheet - Page 20

• Manufacturer Part Number: MAX9526
• Description: High-Performance NTSC/PAL Video Decoder
• Manufacturer: Maxim Integrated Products

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Low-Power, High-Performance
NTSC/PAL Video Decoder
Send the slave address with the R/W bit set to 1 to initi-
ate a read operation. The MAX9526 acknowledges
receipt of its slave address by pulling SDA low during
the 9th SCL clock pulse. A START (S) command fol-
lowed by a read command resets the address pointer
to register 0x00.
The first byte transmitted from the MAX9526 is the con-
tents of register 0x00. Transmitted data is valid on the
rising edge of SCL. The address pointer autoincre-
ments after each read data byte. This autoincrement
feature allows all registers to be read sequentially within
one continuous frame. A STOP (P) condition can be
issued after any number of read data bytes. If a STOP
condition is issued followed by another read operation,
the first data byte to be read is from register 0x00.
Figure 9. I
Figure 10. START, STOP, and REPEATED START Conditions
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SCL
SDA
______________________________________________________________________________________
.
SDA
SCL
D
2
C Serial Interface Timing Diagram
t
HD: STA
a
S
CONDITION
t
START
a
S
t
h
LOW
e
t
R
Sr
e
t
t
SU: DAT
HIGH
t
Read Data Format
t
F
4
U
t
HD: DAT
.
P
c
o
t
m
SU: STA
START CONDITION
The address pointer can be preset to a specific register
before a read command is issued. The master presets
the address pointer by first sending the MAX9526’s
slave address with the R/W bit set to 0 followed by the
register address. A REPEATED START (Sr) condition is
then sent followed by the slave address with the R/W bit
set to 1. The MAX9526 then transmits the contents of
the specified register. The address pointer autoincre-
ments after transmitting the first byte.
The master acknowledges receipt of each read byte
during the acknowledge clock pulse. The master must
acknowledge all correctly received bytes except the
last byte. The final byte must be followed by a not
acknowledge from the master and then a STOP condi-
tion. Figure 14 illustrates the frame format for reading
one byte from the MAX9526. Figure 15 illustrates the
frame format for reading multiple bytes from the
MAX9526.
Figure 11. Acknowledge
REPEATED
SDA
SCL
CONDITION
START
t
HD: STA
1
t
2
SP
t
SU: STO
NOT ACKNOWLEDGE
CONDITION
ACKNOWLEDGE
STOP
8
ACKNOWLEDGMENT
CLOCK PULSE FOR
t
BUF
CONDITION
START
9