Start And Stop Of Video Capturing - NEC µPD72257 Preliminary User's Manual

Video Input (Ravin-M only)
Interlaced video

6.3.2 Start and stop of video capturing

Note
Start of capturing
Stop of capturing
Further no scanline interrupt VInSCLINT, caused by any first field interrupt, will be
generated.
In case an interlaced scanned video is detected, the video data is stored in two
separate framebuffers, depending on the field:
• video data of field 1 is store in the framebuffer, starting at address
VInSTARTADDR1
• video data of field 2 is store in the framebuffer, starting at address
VInSTARTADDR2
The scanline monitor register VInACTSCANLINE provides information about the
current scanline in form of the field indicator VInACTSCANLINE.AFLD and the
current line number VInACTSCANLINE.ACTSL[11:0] for indicated field. Thus the
linecounter counts from 0 to the half of the total number of scanlines.
If the scanline interrupts for both fields are enabled (VInSCANLINEINT.FLD1EN =
VInSCANLINEINT.FLD2EN = 1), VInSCLINT is generated once per field, i.e. twice
per frame.
The Video Input module requires to be enabled by setting the bit
SYSVIEN.VIEN = 1 in the System Controller.
If the Video Input module is disabled by SYSVIEN.VIEN = 0 all Video Input
registers can be accessed, but writing to the registers is ignored and reading
returns undefined values.
Below describes the sequence of how to start up the capturing of video data:
1. enable the Video Input module by SYSVIEN.VIEN = 1
2. define the Video Input data format and the synchronization method
by setting VInCONTROL.RGBEN, VInCONTROL.RGBSEL or
VInCONTROL.YUVSEL, VInCONTROL.SYNCSEL[1:0],
VInCONTROL.SYNCINV
3. define the dithering parameter by setting VInCONTROL.DITHEN[3:0]
4. define the frambuffer start addresses in VInSTARTADDR1 and
VInSTARTADDR2
5. define the video size by setting VInSCALEDWIDTH and
VInSCALEDHEIGHT
6. define the first pixel and line to capture by setting VInSTARTX and
VInSTARTY
7. define the scaling factors by setting VInSCALING
8. enable video capturing by setting VInCONTROL.CAPEN = 1
In order to stop video capturing proceed as follows:
1. disable video capturing by setting VInCONTROL.CAPEN = 0
2. wait the time of one complete frame
3. disable the Video Input module by SYSVIEN.VIEN = 0
Preliminary User's Manual S19203EE1V3UM00
Chapter 6
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