TLC320AC02C Datasheet, PDF (34/84 Pages) Texas Instruments – Single-Supply Analog Interface Circuit

2.18.1 Primary Serial Communications Data Format
D15 D14 D13 D12 D11 D10 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00
14-bit DAC Conversion Result
2s-Complement Format†
Control Bits
† _{Since the supply voltage is single ended, the reference for 2s-complement format is ADC VMID. Voltages above}
this reference have a 0 as the MSB, and voltages below this reference have a 1 as the MSB.
During primary serial communications, when D01 and D00 are both high in the DAC data word to DIN, a
subsequent 16 bits of control information is received by the device at DIN during a secondary
serial-communication interval. This secondary serial-communication interval begins at 1/2 the programmed
conversion time when the B register data value is even or 1/2 the programmed value minus one FCLK when
the B register data value is odd. The time between primary and secondary serial communication is
measured from the falling edge of the primary frame sync to the falling edge of the secondary frame sync
(see Section 2.19 for function and format of control words).
2.18.2 Data Format From DOUT During Primary Serial Communications
D15 D14 D13 D12 D11 D10 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00
14-Bit ADC Conversion Result
2s-Complement Format
D15 is the Sign Bit
NJ + Master Mode D01 0
+ D00 0
NJ + Slave Mode D01 0
+ D00 1
2.19 Secondary Serial Communications
2.19.1 Data Format to DIN During Secondary Serial Communications
There are nine 16-bit configuration and control registers numbered from zero to eight. All register data
contents are represented in 2s-complement format. The general format of the commands during secondary
serial communications is as follows.
DS15 DS14 DS13 DS12 DS11 DS10 DS09 DS08 DS07 DS06 DS05 DS04 DS03 DS02 DS01 DS00
Control Bits R/W
(2 bits)
Bit
Register Address
(5 bits)
Register Data Value
(8 bits)
All control register words are latched in the register and valid on the sixteenth falling edge of SCLK.
2.19.2 Control Data-Bit Function in Secondary Serial Communication
2.19.2.1 DS15 and DS14
In the secondary data word, bits DS15 and DS14 perform the same control function as the primary control
bits D01 and D00 do in the primary data word.
DS15 DS14 DS13 DS12 DS11 DS10 DS09 DS08 DS07 DS06 DS05 DS04 DS03 DS02 DS01 DS00
Control Bits R/W
Register Address
Register Data
Hardware terminals FC1 and FC0 are valid inputs when DS15 and DS14 are both high, and they are ignored
for all other conditions.
2–19