TVP5146M2 Datasheet, PDF (32/107 Pages) Texas Instruments – NTSC/PAL/SECAM 4×10-Bit Digital Video Decoder With Macrovision™ Detection, YPbPr Inputs, 5-Line Comb Filter, and SCART Support

TVP5146M2
SLES141H – JULY 2005 – REVISED FEBRUARY 2012
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2.6 I²C Host Interface
Communication with the TVP5146M2 decoder is via an I²C host interface. The I²C standard consists of
two signals, the serial input/output data (SDA) line and the serial input clock line (SCL), which carry
information between the devices connected to the bus. A third signal (I2CA) is used for slave address
selection. Although an I²C system can be multimastered, the TVP5146M2 decoder functions as a slave
device only.
Because SDA and SCL are kept open drain at a logic-high output level or when the bus is not driven, the
user must connect SDA and SCL to a positive supply voltage via a pullup resistor on the board. The slave
addresses select signal, terminal 37 (I2CA), enables the use of two TVP5146M2 devices tied to the same
I²C bus, because it controls the least-significant bit of the I²C device address.
Table 2-4. I²C Host Interface Terminal Description
SIGNAL
I2CA
SCL
SDA
TYPE
I
I/O
I/O
DESCRIPTION
Slave address selection
Input/output clock line
Input/output data line
2.6.1 Reset and I²C Bus Address Selection
The TVP5146M2 decoder can respond to two possible chip addresses. The address selection is made at
reset by an externally supplied level on the I2CA terminal. The TVP5146M2 decoder samples the level of
terminal 37 at power up or at the trailing edge of RESETB and configures the I²C bus address bit A0.
Table 2-5. I²C Address Selection
A6
A5
A4
A3
A2
A1
A0 (I2CA)
R/W
1
0
1
1
1
0
0 (default)
1/0
1
0
1
1
1
0
1 ⁽¹⁾
1/0
(1) If terminal 37 is strapped to DVDD via a 2.2-kΩ resistor, I²C device address A0 is set to 1.
HEX
B9/B8
BB/BA
2.6.2 I²C Operation
Data transfers occur using the following illustrated formats.
S
10111000
ACK
Subaddress
ACK
Send Data
ACK
P
Read from I²C control registers
S
10111000
ACK Subaddress ACK
S
10111001 ACK Receive Data NAK
P
S = I²C bus start condition
P = I²C bus stop condition
ACK = Acknowledge generated by the slave
NAK = Acknowledge generated by the master, for multiple-byte read master with ACK each
byte except last byte
Subaddress = Subaddress byte
Data = Data byte. If more than one byte of data is transmitted (read and write), the
subaddress pointer is automatically incremented.
I²C bus address = Example shown that I2CA is in default mode [write (B8h), read (B9h)]
32
Functional Description
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