mode=slave, tp_en=normal, en=disable, mode_selec=old_mode
SPI Global Control Register
| en | SPI Module Enable Control 0 (disable): undefined 1 (enable): undefined |
| mode | SPI Function Mode Select 0 (slave): undefined 1 (master): undefined |
| mode_selec | Sample timing Mode Select 0 (old_mode): Old mode of Sample Timing 1 (new_mode): New mode of Sample Timing |
| tp_en | Transmit Pause Enable 0 (normal): normal operation, ignore RXFIFO status 1 (stop_when_full): Stop transmit data when RXFIFO full |
| srst | Soft reset |