EP7211 Datasheet, PDF (65/166 Pages) Cirrus Logic – HIGH-PERFORMANCE ULTRA-LOW-POWER SYSTEM-ON-CHIP WITH LCD CONTROLLER

EP7211
High-Performance Ultra-Low-Power System-on-Chip with LCD Controller
Figure 3-9. Video Buffer Mapping shows the organization of the video map for all combinations
of bits per pixel.
Pixel 1 Pixel 2 Pixel 3 Pixel 4
Grey scale
Grey scale
Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7
4 Bits per pixel
Pixel 1 Pixel 2 Pixel 3 Pixel 4
Grey scale Grey scale Grey scale Grey scale
Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7
2 Bits per pixel
Pixel 1 Pixel 2 Pixel 3 Pixel 4
Grey scale Grey scale Grey scale Grey scale
Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7
1 Bit per pixel; in the normal Operating State
Pixel 1 Pixel 2 Pixel 3 Pixel 4
Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7
1 Bit per pixel; in the Standby State
Figure 3-9. Video Buffer Mapping
The refresh rate is not affected by the number of bits per pixel; however the LCD controller fetches
twice the data per refresh for 4-bits-per-pixel compared to 2-bits-per-pixel. The main reason for
reducing the number of bits per pixel is to reduce the power consumption of the memory where the
video frame buffer is mapped.
DS352PP3
JUL 2001
65
Functional Description