NXP Semiconductors MPC5606S - CRC Area Description

Display Control Unit (DCU)
MPC5606S Microcontroller Reference Manual, Rev. 7
Freescale Semiconductor 433
If the user has set NEG bit for DCU which indicates that the pixels fed to the display are inverted of output
pixels, value CRC would be calculated on non inverted values. The position CRC however remains as it is.
In case a pixel has FG0 and FG1 as two highest priority layers with safety mode enabled in layer 1, normal
arbitration takes place.
The polynomial used for CRC calculation is
(x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1)
Figure 12-76. Safety mode block diagram
12.7.1 CRC area description
12.7.1.1 Relationship between various input signals
1. CRC is calculated when Safety mode is enabled.
2. CRC can be calculated over full screen as shown in Figure 12-77. Here tag bit (generated internal
to DCU and flow along the data path) is set low. Data enable is coming for green color portion
given in Figure 12-77. Data enable is not affected by chroma keying. TAG_EN register bit is low
in this case.
Format
Converter
Blending/
Chroma
Key
Gamma
Correc.
Display
Drive
Display
FGPlane
BGPlane
1-32 bpp
1-32 bpp
24 bpp
24 bpp
24 bpp
24 bpp
Format
Converter
Gamma
Correction
Display
Drive
Display
FGPlane
FG1Plane
1-24 bpp
1-24 bpp
25 bpp
25 bpp
25 bpp 24 bpp
Signature
Calculator
Normal mode operation
Safety mode
optional
Chroma
Key
optional
sync tag
25 bpp = 24 bpp RGB + 1 bit safety pixel tag
optional
external
signature
checker
Result
Interrupt
calculator
FG2Plane
1-24 bpp
BGPlane
1-24 bpp