ONFI PHY write direction training method supporting independent adjustment of Bit Line in high-speed mode

The invention relates to the technical field of chip data reading, in particular to an ONFI PHY write direction training method supporting independent adjustment of Bit Line in a high-speed mode. Searching a lower boundary value of the window, if the Delayx is not equal to 0, subtracting 1 from the Delayx until the data written on the BitLinex is wrong; if the data is wrong, adding 1 to the Delayx, and then executing the write direction training instruction with the configurable number of times, if the data is wrong, adding 1 to the Delayx, and then executing the write direction training instruction with the configurable number of times; searching an upper boundary value of the window, adding 1 to Delayx until the Delayx is added to BitLinex, and writing a data error; and if the data error occurs, subtracting 1 from the Delayx, and then executing the write direction training with configurable times until the instruction is ended, so that the write direction training precision can be improved, and the data sam