Vertical Generation Configuration Example with Active Chroma for YUV 4:2:0 Active for Odd Lines

Programming the vertical generation registers to the values shown in Table: Example Vertical Generation Register Inputs (Alternate 4:2:0 Chroma) will result in the video timing signal outputs shown in This Figure .

Notice that the Generator Encoding Register bits [3:0] are set to 0b0011, as in the previous example. Bits [9:8] of the Generator Encoding Register is set to 1 instead of 0. This configures the Active Chroma output signal for 4:2:0 mode, but with the opposite line set.

Table 3-4: Example Vertical Generation Register Inputs (Alternate 4:2:0 Chroma)
Register Address	Register Name	Value
0x0060	Generator Active Size	0x0004_0003
0x0070	Generator HSize	0x0000_0007
0x0074	Generator VSize	0x0000_0008
0x0078	Generator HSync	0x0005_0004
0x0080	Generator Frame 0 Vsync	0x0006_0005
0x0068	Generator Encoding	0x0000_0103
0x006C	Generator Polarity	0x0000_003f
0x0000	Control	0x01ff_ff07

Figure 3-6: Generated Vertical Timing (Alternate 4:2:0 Chroma)
X-Ref Target - Figure 3-6

The following C code shows how to configure the register values in Table: Example Vertical Generation Register Inputs (Alternate 4:2:0 Chroma) using the Video Timing Controller driver.

XVtc Vtc; /* Device driver instance */

XVtc_Signal SignalCfg; /* VTC Signal configuration */

XVtc_Polarity Polarity; /* Polarity configuration */

XVtc_SourceSelect SourceSelect;/* Source Selection configuration */

XVtc_Config *VtcCfgPtr;

VtcCfgPtr = XVtc_LookupConfig(VTC_DEVICE_ID);

XVtc_CfgInitialize(&Vtc, VtcCfgPtr, VtcCfgPtr->BaseAddress);

/* Setup the VTC Source Select config structure. */

/* 1=Generator registers are source */

/* 0=Detector registers are source */

memset((void *)&SourceSelect, 0, sizeof(SourceSelect));

SourceSelect.VBlankPolSrc = 1;

SourceSelect.VSyncPolSrc = 1;

SourceSelect.HBlankPolSrc = 1;

SourceSelect.HSyncPolSrc = 1;

SourceSelect.ActiveVideoPolSrc = 1;

SourceSelect.ActiveChromaPolSrc= 1;

SourceSelect.VChromaSrc = 1;

SourceSelect.VActiveSrc = 1;

SourceSelect.VBackPorchSrc = 1;

SourceSelect.VSyncSrc = 1;

SourceSelect.VFrontPorchSrc = 1;

SourceSelect.VTotalSrc = 1;

SourceSelect.HActiveSrc = 1;

SourceSelect.HBackPorchSrc = 1;

SourceSelect.HSyncSrc = 1;

SourceSelect.HFrontPorchSrc = 1;

SourceSelect.HTotalSrc = 1;

/* Setup the VTC Polarity config structure. */

memset((void *)&Polarity, 0, sizeof(Polarity));

Polarity.ActiveChromaPol = 1;

Polarity.ActiveVideoPol = 1;

Polarity.VBlankPol = 1;

Polarity.VSyncPol = 1;

Polarity.HBlankPol = 1;

Polarity.HSyncPol = 1;

/* Setup the VTC Signal config structure. */

memset((void *)&SignalCfg, 0, sizeof(XVtc_Signal));

SignalCfg.OriginMode = 1;//Set Frame Origin to Start of Active Video

SignalCfg.HTotal = 7;

SignalCfg.HActiveStart = 0;

SignalCfg.HFrontPorchStart = 3;// Active Video Width

SignalCfg.HSyncStart = 4;// Active Video Width + FP Width

SignalCfg.HBackPorchStart = 5;// Active Video Width + FP Width + Sync Width

SignalCfg.V0Total = 8;

SignalCfg.V0ChromaStart = 0;

SignalCfg.V0ActiveStart = 1;

SignalCfg.V0FrontPorchStart = 4;// Active Video Height

SignalCfg.V0SyncStart = 5;// Active Video Height + FP_Width

SignalCfg.V0BackPorchStart = 6;// Active Video Height + FP Width + Sync Width

/* Write VTC config to HW */

XVtc_RegUpdate(&VTC);

XVtc_SetPolarity(&Vtc, &Polarity);

XVtc_SetGenerator(&Vtc, &SignalCfg);

XVtc_SetSource(&Vtc, &SourceSelect);

XVtc_SetSkipLine(&Vtc, 1);

/* Enable VTC Generator */

XVtc_Enable Generator(&Vtc);

Vertical Generation Configuration Example with Active Chroma for YUV 4:2:0 Active for Odd Lines - 6.2 English

Video Timing Controller Product Guide (PG016)