881
SAM4CP [DATASHEET]
43051E–ATPL–08/14
The advantages of this solution are:
Ability to access the user buffer at any time in the frame, in any display mode and even in low-power waveform.
Ability to change only one pixel without reloading the picture.
39.6.5 Display Features
In order to improve the flexibility of SLCDC the following set of display modes are embedded:
1.
Force Mode Off: All pixels are turned off and the memory content is kept.
2.
Force Mode On: All pixels are turned on and the memory content is kept.
3.
Inverted Mode: All pixels are set in the inverted state as defined in SLCDC memory and the memory content is
kept.
4.
Two Blinking Modes:
Standard Blinking Mode:
All pixels are alternately turned off to the predefined state
in SLCDC memory at
LCDBLKFREQ frequency.
Inverted Blinking Mode: All pixels are alternately turned off to the predefined opposite state in SLCDC
memory at LCDBLKFREQ frequency.
5.
Buffer Swap Mode: All pixels are alternatively assigned to the state defined in the user buffer then to the state
defined in the display buffer.
39.6.6 Buffer Swap Mode
This mode allows 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 a 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 wanted 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.
39.6.7 Disabling the SLCDC
There are two ways to disable the SLCDC:
1.
By using the SLCDC_CR [LCDDIS] bit (recommended method). In this case, SLCDC configuration and memory
content are maintained.
2.
By using the SWRST (Software Reset) bit that acts like a hardware reset for SLCDC only.
Both methods are described in the following sections.