JAJSFT4C August 2018 – June 2019 ADS9224R , ADS9234R
PRODUCTION DATA.
In this data transfer protocol, the bus width of reading data from each ADC can be increased to two SDOs or four SDOs. All combinations of clock phase and polarity are supported. The read time required for reading the output data word reduces with increases in bus width and, thus, tCYCLE for zone 1 transfer reduces. The SDOs that are not enabled by the BUS_WIDTH register are set to tri-state. Table 4 provides the details of different SPI protocols with bus width options and single data rate to read data from the device.
PROTOCOL(3) | SCLK POLARITY (CPOL)(4) | SCLK PHASE (CPHA)(1)(2) | MSB LAUNCH EDGE | BUS WIDTH(7) | tREAD(5)(6) | TIMING DIAGRAM |
---|---|---|---|---|---|---|
SPI-00-D-SDR | Low (CPOL = 0) | Rising (CPHA = 0) | CS falling | 2 | [7.5 × tCLK + k] | Figure 49 |
SPI-01-D-SDR | Low (CPOL = 0) | Falling (CPHA = 1) | 1st SCLK rising | 2 | [7.5 × tCLK + k] | Figure 50 |
SPI-10-D-SDR | High (CPOL = 1) | Falling (CPHA = 0) | CS falling | 2 | [7.5 × tCLK + k] | Figure 49 |
SPI-11-D-SDR | High (CPOL = 1) | Rising (CPHA = 1) | 1st SCLK falling | 2 | [7.5 × tCLK + k] | Figure 50 |
SPI-00-Q-SDR | Low (CPOL = 0) | Rising (CPHA = 0) | CS falling | 4 | [3.5 × tCLK + k] | Figure 51 |
SPI-01-D-SDR | Low (CPOL = 0) | Falling (CPHA = 1) | 1st SCLK rising | 4 | [3.5 × tCLK + k] | Figure 52 |
SPI-10-D-SDR | High (CPOL = 1) | Falling (CPHA = 0) | CS falling | 4 | [3.5 × tCLK + k] | Figure 51 |
SPI-11-D-SDR | High (CPOL = 1) | Rising (CPHA = 1) | 1st SCLK falling | 4 | [3.5 × tCLK + k] | Figure 52 |
Figure 49, Figure 50, Figure 51, and Figure 52 show timing diagrams for the SPI-00-D-SDR and SPI-10-D-SDR, SPI-01-D-SDR and SPI-11-D-SDR, SPI-00-Q-SDR and SPI-10-Q-SDR, and SPI-01-Q-SDR and SPI-11-Q-SDR protocols, respectively.