PXD10RM Datasheet, PDF (435/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

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)
Normal Mode Operation
1-32 bpp
FGPlane
Format
Converter
1-32 bpp
BGPlane
24 bpp ^Blending/ 24 bpp ^Gamma
Chroma
Correc.
Key
Display
24 bpp
Drive
24 bpp _Display
Safety Mode
1-24 bpp
FGPlane
1-24 bpp
FG1Plane
1-24 bpp
FG2Plane
Format
Converter
25 bpp ^optional
Chroma
Key
1-24 bpp
BGPlane
25 bpp ^optional
Gamma
Display
25 bpp _Drive
Correction
24 bpp
sync tag
25 bpp = 24 bpp RGB + 1 bit safety pixel tag
Result
Interrupt
Signature
Calculator
Display
optional
external
signature
calculator
checker
Figure 12-77. 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 12-78. Here tag bit (generated internal
to DCU and flow along the datapath) is set low. Data enable is coming for green color portion given
in Figure 12-78. Data enable is not affected by chroma keying. TAG_EN register bit is low in this
case.
Freescale Semiconductor
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
12-103