AN2676 Freescale Semiconductor / Motorola, AN2676 Datasheet - Page 11

• Manufacturer Part Number: AN2676
• Description: Image Capture with i.MX21
• Manufacturer: Freescale Semiconductor / Motorola

Freescale Semiconductor, Inc.
Software Design
Init
CSI Port Enable
CSI Timing Config
Enable HCLK
Enable sync FIFO clear
Enable MCLK
Enable SOF Interrupt
Init I2C
Init DMA
Init Sensor
Return
ISR for CSI
ISR for DMA
SOF_INT = ‘1’?
DISR = ‘1’?
N
Y
Write ‘1’ to SOF_INT
Write ‘1’ to DISR
N
DMA complete
flag set?
Set DMA
Set DMA
Y
complete flag
error flag
Enable DMA channel
Return
Miss
Frame
Clear DMA complete flag
Return
Figure 9. DMA Non-Repeat Mode
8.2 CSI with PRP
Data is transferred by a private bus from CSI FIFO to the eMMA-PRP module. After the bus is enabled,
the image data is forwarded to the PRP continuously, and the path to DMA is switched off by internal
logic. No CSI FIFO interrupts are generated.
The PRP module is able to accept RGB565 or YUV422 data from CSI. Data formats are shown in Table 5
on page 12. RGB565 data is Big-endian while YUV422 data is Little-endian.
MOTOROLA
MC9328MX21 Application Note
11
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