SPI0 control register.
| FDUMMY_OUT | In the DUMMY phase the signal level of SPI bus is output by the SPI0 controller. |
| FDOUT_OCT | Set this bit to enable 8-bit-mode(8-bm) in DOUT phase. |
| FDIN_OCT | Set this bit to enable 8-bit-mode(8-bm) in DIN phase. |
| FADDR_OCT | Set this bit to enable 8-bit-mode(8-bm) in ADDR phase. |
| FCMD_DUAL | Set this bit to enable 2-bit-mode(2-bm) in CMD phase. |
| FCMD_QUAD | Set this bit to enable 4-bit-mode(4-bm) in CMD phase. |
| FCMD_OCT | Set this bit to enable 8-bit-mode(8-bm) in CMD phase. |
| FASTRD_MODE | This bit should be set when SPI_MEM_FREAD_QIO, SPI_MEM_FREAD_DIO, SPI_MEM_FREAD_QUAD or SPI_MEM_FREAD_DUAL is set. |
| FREAD_DUAL | In hardware 0x3B read operation, DIN phase apply 2 signals. 1: enable 0: disable. |
| Q_POL | The bit is used to set MISO line polarity, 1: high 0, low |
| D_POL | The bit is used to set MOSI line polarity, 1: high 0, low |
| FREAD_QUAD | In hardware 0x6B read operation, DIN phase apply 4 signals(4-bit-mode). 1: enable 0: disable. |
| WP | Write protect signal output when SPI is idle. 1: output high, 0: output low. |
| FREAD_DIO | In hardware 0xBB read operation, ADDR phase and DIN phase apply 2 signals(2-bit-mode). 1: enable 0: disable. |
| FREAD_QIO | In hardware 0xEB read operation, ADDR phase and DIN phase apply 4 signals(4-bit-mode). 1: enable 0: disable. |