SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The SPI data shifter handles the capture and generation of the SPI interface signals. Based on control signals from the SPI_MACHINE and SPI_CNTIF blocks, data is shifted in or out on falling or rising edge of qspi0_sclk clock depending on the SPI clock mode selected. Table 13-258 lists the four defined clock modes of operation for the QSPI.
Mode | Settings in the QSPI_SPI_DC_REG Register | Description | |
---|---|---|---|
Value of the CKP bits | Value of the CKPH bits | ||
0 | 0 | 0 | Data input captured on falling edge of qspi0_sclk clock. Data output generated on falling edge of qspi0_sclk clock |
1 | 0 | 1 | Data input captured on rising edge of qspi0_sclk clock. Data output generated on rising edge of qspi0_sclk clock |
2 | 1 | 0 | Data input captured on rising edge of qspi0_sclk clock. Data output generated on rising edge of qspi0_sclk clock |
3 | 1 | 1 | Data input captured on falling edge of qspi0_sclk clock. Data output generated on falling edge of qspi0_sclk clock |
Mode 1 and Mode 2 are not supported and should not be used.
The CKPi and CKPHi (i = 0 to 3) bits of the QSPI_SPI_DC_REG register control the clock modes. Each of these 4 bits corresponds to an output chip select.
Figure 13-203 shows all four clock modes. In addition, through the DDi (i = 0 to 3) bits of the QSPI_SPI_DC_REG register the data can be delayed from one to three qspi0_sclk clock cycles after the corresponding qspi0_cs[n] (n = 0 to 1) goes active. The active state of each chip-select can also be controlled through the CSPi (i = 0 to 3) bits of the QSPI_SPI_DC_REG register.