SPI Timing Format

SPI commands are used to communicate between the host and the COG driver. The SPI format used differs from the standard in that two-way communications are not used.

When setting up the SPI timing, PDI recommends verifying both the SPI command format and the SPI command timing in this section.

The maximum clock speed of the display is 20MHz (Write), 2.5MHz (Read).

Step	Register	CS pin	Data/Value	Name/Unit	Comment
SPI	0x01	Both	OTP[0x10], 0x00	DCTL	2 bytes of data, first DCTL then 0x00

• Register is the register index, in the example above 0x01
• CS Pin indicates which driver is selected for command:
  • Master : only deliver to Master driver
  • Slave : only deliver to Slave driver
  • Both : deliver to both Master and Slave
  • Selecting the proper driver requires toggling both Master and Slave CS pins, as seen in the flowchart below
• Data/Value could be
  • A fixed value, for example 0x00
  • Values read from the OTP memory at OTP index
  • Multiple values, in the example the OTP value from address 0x10 and 0x00
• The D/C line is pulled LOW for command and HIGH for data.

SPI Command Timing

The following specifications apply for VDDIO - GND = 2.3V to 3.6V, TOPR = 25°C, CL=20pF