36.6.6 Buffer Swap Mode

This mode is used to assign all pixels to two states alternatively without reloading the user buffer at each change.

The means to alternatively display two states is as follows:

  1. Initially, the SLCDC must be in Normal mode or in Standard Blinking mode.
  2. Data corresponding to the first pixel state is written in the user buffer (through the SLCDC_MEM registers).
  3. Wait two ENDFRAME events (to be sure that the user buffer is entirely transferred in the display buffer).
  4. SLCDC_DR must be programmed with DISPMODE = 6 (User Buffer Only Load mode). This mode blocks the automatic transfer from the user buffer to the display buffer.
  5. Wait ENDFRAME event. (The display mode is internally updated at the beginning of each frame.)
  6. Data corresponding to the second pixel state is written in the user buffer (through the SLCDC_MEM registers). So, now the first pixel state is in the display buffer and the second pixel state is in the user buffer.
  7. SLCDC_DR must be programmed with DISPMODE = 7 (Buffer Swap mode) and LCDBLKFREQ must be programmed with the required blinking frequency (if not previously done).

Now, each state is alternatively displayed at LCDBLKFREQ frequency.

Except for the phase dealing with the storage of the two display states, the management of the Buffer Swap mode is the same as the Standard Blinking mode.