Waveshare 7.3inch e-Paper (E) - Page 10

7.3inch e-Paper (E)
User Manual
7
Note 5-5: This pin (BS0) is for 3-line SPI or 4-line SPI selection. When it is “Low”, 4-line SPI is selected.
When it is “High”, 3-line SPI (9 bits SPI) is selected. Please refer to below Table.
Table: Bus interface selection
BS0 State
MCU Interface
L
4-lines serial peripheral interface(SPI)
H
3- lines serial peripheral interface(SPI) - 9 bits SPI