PXD20RM Datasheet, PDF (562/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

12.7.1 CRC area description
12.7.1.1 Configuring the CRC calculation
1. CRC_VAL and CRC_POS are calculated when Safety Mode is enabled using
DCU_MODE[SIG_EN].
2. The CRC can be calculated for part of the panel as shown in Figure 12-85. The green portion on
the panel is identified using the SIGN_CALC_1 and SIGN_CALC_2 registers which defined the
size of the area and the location of the area respectively. If SIGN_CALC_1 and SIGN_CALC_2
are configured appropriately this calculation will cover the whole panel.
area of concern
StartY
LenX
StartX
LenY
Note: Enable to CRC is sent for the
Green Portion
Figure 12-85. Safety Mode enabled for part of the screen
3. The CRC can be calculated exclusively for layers 0 and 1 by setting DCU_MODE[TAG_EN] and
enabling the SAFETY_EN bit in control descriptor 4 of each of the layers. In this configuration the
CRC is calculated using values from the layers only where they intersect the area of interest defined
in SIGN_CALC_1 and SIG_CALC_2. An example is shown (in dark pink) in Figure 12-86.
12-100
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor