The DPC3090 iLCD Controller offers an on-chip EEPROM for user data. DPC3050 and DPC3080 controllers contain an EEPROM emulation behaving like a real EEPROM, which means that you can write any value into any memory location at any time. This is different to usual Flash memory behavior, which must be erased before overwriting a value. The only difference to a real EEPROM is that in rare cases, the write process may take up to one second due to organizational overhead. During this period no other commands can be carried out. For example, blinking outputs or animated graphics are stopped. Any data sent to the iLCD Controller during this period will be lost as well.
The EEPROM emulation on DPC3050 controllers provides 240 bytes and on DPC3080 496 byte of space; the DPC3090's EEPROM has a size of 4016 bytes. Only the first 9 values are used by the iLCD Controller itself, however these values can be freely written to. Any other location may be used for the controlling application to store and retrieve its private data which is kept, even after a power loss.
The 9 special values affect the default startup values for the LCD
| Location | Contents | Range of Values | Reference |
|---|---|---|---|
| 0 | LCD Contrast | 0 ... 255 | Set LCD Contrast |
| 1 | LCD Backlight Intensity | 0 ... 15 | Set Backlight Intensity |
| 2 | LCD Backlight Mode | 0 ... 2 | Set Backlight Mode |
| 3 | LCD Gamma Value | 0 ... 255 | Set LCD Gamma Value |
and the (optional) PCAP touch screen
| Location | Contents | Range of Values | Reference |
|---|---|---|---|
| 4 | PCAP Number of Fingers | 1 ... 5 | Set Number of Touch Fingers |
| 5 | PCAP Threshold | 0 ... 255 | iLCD Manager XE |
| 6 | PCAP Gain | 0 ... 255 | iLCD Manager XE |
| 7 | PCAP Offset | 0 ... 255 | iLCD Manager XE |
| 8 | PCAP Checksum | 0 ... 255 | iLCD Manager XE |
Although any value can be written to any location, the iLCD Controller will automatically restrict values to the corresponding range when retrieving data from the LCD (first 4) values of the EEPROM.
It is recommended to modify the PCAP values in the "Properties" window found on iLCD Manager XE's "Device" page, the checksum is then automatically calculated and written. If the checksum is not valid, factory default values are loaded at startup and written to EEPROM. To set the factory defaults manually, refer to Set PCAP Configuration to Factory Default. It is also possible to set the PCAP values with the Write EEPROM command. Therefore the PCAP Checksum is calculated with: Checksum = (byte) (NumberOfFingers + Threshold + Gain + Offset). All values have to be unsigned byte.
The 9 values mentioned above are restored from the EEPROM and the corresponding internal commands (e.g. for setting the backlight intensity) are carried out at startup (also when a Reboot Panel Controller is issued) and when a Reset All or a Reset All and Show Startup Graphic command is sent to the controller.
Please note that writing to the 9 special EEPROM locations via the Write EEPROM command does not call the associated command. The new settings will only become active upon startup. When you want to set something like the backlight intensity, use the appropriate command instead of – or in addition to – the Write EEPROM command.
Find following commands in this chapter as well as in the corresponding category when using the parameter completion feature of iLCD Manager XE:
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