BWRY Medium¶
The document introduces how to drive the Pervasive Displays 5.8” and 7.4” BWRY EPD.
The EPD has embedded the Tcon function. The driver’s major control interface is SPI. The host sends the setting commands and the display image to the driver through the SPI bus.
Definition of Operation Modes¶
The section will define the OTP memory and clarify update modes.
OTP memory¶
The OTP memory of the screen controller contains all the parameters to initialise the screen, as well as the waveforms for normal update. The waveforms are specific to each batch of screens and set for optimal image quality.
The OTP memory contains 224 bytes.
The host needs to read the OTP memory once, as long as it retains the values.
There are two bank spaces in the OTP memory. When the data are read out, the first step is to determine which space is the active space (Bank0 or Bank1).
If the address 0 data is “0xa5”, the active space is Bank0; otherwise, the active space is Bank1.
| Entry | Address | Value | Comment |
|---|---|---|---|
| Check Code | 0x1500 | 0xa5 | Checks OTP validity. This check code indicates whether the BANK0 is valid. If so, it would be `0xa5` |
| Pervasive Display Reserves | 0x1501-0x150F | Ignore | |
| COG Initial data | 0x1510-0x1544 | The data of this sector are the necessary IC initial data. |
| Entry | Address | Value | Comment |
|---|---|---|---|
| Check Code | 0x1570 | 0xa5 | Checks OTP validity. This check code indicates whether the BANK0 is valid. If so, it would be `0xa5` |
| Pervasive Display Reserves | 0x1571-0x157F | Ignore | |
| COG Initial data | 0x1580-0x15B4 | The data of this sector are the necessary IC initial data. |
Update modes¶
The screen only supports one update mode.
- Normal update will perform the complete waveform for image update. The process will go through the inverse, flashing and imaging phases. The mode will take more time, but it will bring better image performance.
Panel Drawing¶
5.8"
7.4"