PXD20RM Datasheet, PDF (558/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

12.5.3 Error detection
The DCULite asserts error flags when errors are detected in its configuration or when the user attempts to
modify the configuration at an invalid point in the panel refresh period or when it is unable to access the
required source data. The error flags may raise an interrupt if enabled to do so by the related mask bit in
the corresponding mask register.
Error flags are stored in the PARR_ERR_STATUS and INT_STATUS registers.
Errors in the DCULite configuration are collected in the PARR_ERR_STATUS register. The flags
Ln_PARR_ERR (where n is the layer number) indicate an error in the configuration of the layer which
indicates a layer with a horizontal dimension that is smaller than the minimum size defined by the layer
encoding (see Section 12.4.4.3, Layer size and positioning). The DISP_ERR flag indicates that the
VSYNC and HSYNC pulse widths are configured to the invalid value of 0. The HWC_ERR flag indicates
that the hardware cursor is either larger than the available memory or is placed in an off-panel position.
The SIG_ERR indicates that the signature calculation specifies an area that extends beyond the panel size.
The RLE_ERR indicates that more than one layer has RLE enabled.
Reads of CLUT RAM during the period when the TFT LCD panel is being updated do not return the CLUT
RAM content.
Errors caused when the DCULite is unable to access its required source data are collected in the
INT_STATUS register. These errors are indicated by the UNDRUN flag and the Pm_FIFO_LO_FLAG
flags (where m is the position in the blend stack)
12.5.4 Interrupt generation
The DCULite generates interrupt through four lines that are controlled by the contents of six registers:
• INT_STATUS
• INT_MASK
• PDI_STATUS
• MASK_PDI_STATUS
• PARR_ERR STATUS
• MASK_PARR_ERR STATUS
There are four interrupt status lines defined.These lines are grouped as follows
• Timing based interrupts:
— VSYNC
— LS_BF_VS
— VS_BLANK
— PROG_END
— DMA_TRANS_FINISH
• Functional interrupts:
— UNDRUN
— CRC_READY
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PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor