TLC320AD80 Datasheet, PDF (21/37 Pages) Texas Instruments – Audio Processor Subsystem

The CS input must make a low to high transition in order to specify a new control register address. When
the CS input is set to 1, the serial command data output (CDOUT) is placed in a high-impedance state. When
the CS input is cleared to 0, the CDOUT output is held low during nonvalid data intervals.
The serial control port is activated when the CS signal (active low) goes low. The CS line must be low prior
to data transactions and must remain low for the duration of the transaction. The serial command data input
(CDIN) is sampled on the rising edge of SCLK. The CDIN data is MSB first and unsigned. While the CS input
is low, the SCLK input must idle high when there is no valid data to be transferred. The first byte of CDIN
data after CS activation is set up as a serial control command. The serial control command includes a 4-bit
control register address [D(3–0)] and a control port direction bit (D7). The second byte of data is set up as
control register data. The CS input must make a low-to-high transition in order to specify a new control
register address. When the CS input goes high, the serial command data output (CDOUT) is placed in a
high-impedance state. When the CS input goes low, the CDOUT output is held low during nonvalid data
intervals.
SCLK
CS
CDIN
D7 D6 D5 D4 D3 D2 D1 D0
MSB
Serial Control Command
LSB
D7 D6
MSB
D5 D4 D3 D2
Serial Data
D1 D0
LSB
CDOUT
D7 D6 D5 D4 D3 D2 D1 D0
Figure 2–5. Serial Interface Timing
2.5.2 Serial Control Command Format
The serial control command format is shown below.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _D7
D6
D5
D4
D3
D2
D1
D0
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _WR
Unused
ADDR(3–0)
The serial control command fields are defined as:
WR – Serial interface direction
When this bit is 1:
• The serial interface is in write mode.
• Serial data is sent control register specified in the serial control command
When this bit is 0:
• The serial interface is in read mode.
• The control register data is output to CDOUT according to the control register address.
ADDR(3–0) – Control register address specifies the TLC320AD80 register being accessed.
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