Texas Instruments TMS320DM648 manual Video Capture Fifo Registers Function

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Video Capture FIFO Registers

3.14 Video Capture FIFO Registers

The capture FIFO mapping registers are listed in Table 3-34. These registers provide read access to the capture FIFOs. These pseudo-registers should be mapped into DSP memory space rather than configuration register space in order to provide high-speed access. See the device-specific datasheet for the memory address of these registers. The function of the video capture FIFO mapping registers is listed in Table 3-35.

Table 3-34. Video Capture FIFO Registers

Offset Address (1)	Acronym	Register Name
00h	YSRCA	Y FIFO Source Register A
20h	CBSRCA	Cb FIFO Source Register A
40h	CRSRCA	Cr FIFO Source Register A
00h	YSRCB	Y FIFO Source Register B
20h	CBSRCB	Cb FIFO Source Register B
40h	CRSRCB	Cr FIFO Source Register B

(1)The absolute address of the registers is device/port specific and is equal to the FIFO base address + offset address. See the device-specific datasheet to verify the register addresses.

Table 3-35. Video Capture FIFO Registers Function

Capture Mode

Register BT.656 or Y/C Raw Data TCI

YSRCx Maps Y capture buffer into DSP memory.

CBSRCx Maps Cb capture buffer into DSP memory.

Maps data capture buffer into the DSP memory.

Not used.

Maps data capture buffer into the DSP memory.

Not used.

CRSRCx Maps Cr capture buffer into DSP	Not used.	Not used.
memory.

In BT.656 or Y/C capture mode, three EDMAs move data from the Y, Cb, and Cr capture FIFOs to the DSP memory by using the memory-mapped YSRCx, CBSRCx, and CRSRCx registers. The EDMA transfers are triggered by the YEVT, CbEVT, and CrEVT events, respectively.

In raw capture mode, one EDMA channel moves data from the Y capture FIFO to the DSP memory by using the memory-mapped YSRCx register. The EDMA transfers are triggered by a YEVT event.

The video port packs receive data into 64-bit words in the FIFO and the EDMA should always move 64-bit-wide data from YSRCx, CBSRCx, and CRSRCx to the memory.

SPRUEM1 –May 2007 Video Capture Port 91

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