LM1276AAA National Semiconductor, LM1276AAA Datasheet - Page 25

• Manufacturer Part Number: LM1276AAA
• Description: 150 MHz I2C Compatible RGB Preamplifier with Internal 512 Character OSD ROM, 512 Character RAM and 4 DACs
• Manufacturer: National Semiconductor

Microcontroller Interface
written to is next sent in two bytes, the least significant byte
being sent first. The master can then send the data, which
consists of one or more bytes. Each data byte is followed by
an acknowledge bit. If more than one data byte is sent, the
data will increment to the next address location. See Figure
17.
READ SEQUENCE
Read sequences are comprised of two I
fer sequences: The first is a write sequence that only trans-
fers the two byte address to be accessed. The second is a
read sequence that starts at the address transferred in the
previous address only write access and increments to the
next address upon every data byte read. This is shown in
LM1276 Address Map
2
FIGURE 17. I
FIGURE 18. I
C compatible trans-
(Continued)
2
2
C Compatible Write Sequence
C Compatible Read Sequence
25
Figure 18. The write sequence consists of the Start Pulse,
the Slave Device Write Address (0xBA), and the Acknowl-
edge bit; the next byte is the least significant byte of the
address to be accessed, followed by its Acknowledge bit.
This is then followed by a byte containing the most signifi-
cant address byte, followed by its Acknowledge bit. Then a
Stop bit indicates the end of the address only write access.
Next the read data access will be performed beginning with
the Start Pulse, the Slave Device Read Address (0xBB), and
the Acknowledge bit. The next 8 bits will be the read data
driven out by the LM1276 preamp associated with the ad-
dress indicated by the two address bytes. Subsequent read
data bytes will correspond to the next increment address
locations. Data should only be read from the LM1276 when
both OSD windows and the Fade In/ Fade Out are disabled.
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