SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
When Active Matrix Display is used the following registers must be set:
The size of and panel is defined by:
Standard HSYNC/VSYNC timing generation are programmable for each LCD outputs independently:
When the output is in BT.1120 or BT.656 mode, the following timing constant are mapped onto the DISPC_TIMING_Ho and DISPC_TIMING_Vo registers:
Horizontal/vertical synchronization and ACBIAS signals polarity are programmable by setting the DISPC_POL_FREQo[12] IVS, DISPC_POL_FREQo[13] IHS, and DISPC_POL_FREQo[15] IEO bits. These signals can be gated by setting the DISPC_CONFIGo[7] VSYNCGATED and DISPC_CONFIGo[6] HSYNCGATED bits.
The latch of data can be driven on the rising or falling edge of the pixel clock by setting the IPC bit of DISPC_POL_FREQo[14] IPC and CTRL_CORE_SMA_SW_1[] DSS_CHx_IPC (the values must mach) registers. The drive of the SYNC and VSYNC signals in the function of the pixel clock is done by setting the DISPC_POL_FREQo[16] RF and CTRL_CORE_SMA_SW_1[] DSS_CHx_RF bit.
Table 11-89 describes the programming rules for LCD timing.
No Downsampling | Downsampling H or V | Downsampling H + V | |
---|---|---|---|
(HBP + HSW + HFP) × PCD | >8 | >10 | >20 |
Figure 11-92 shows the timing values description in the case of an active matrix display.
The 8-bit pixel clock divider (the DISPC_DIVISORo[7:0] PCD bit field) selects the pixel clock frequency. This bit field generates a range of pixel clock frequencies from LC/2 to LC/256, where LC is the logic clock from the divided functional clock of the DISPC by the DISPC_DIVISOR[23:16] LCD bit field.
The pixel clock is defined by the following equation:
Pixel Clock = (FunctionalClock/LCD[7:0])/PCD[7:0]
The pixel clock can be gated by setting the DISPC_CONFIGo[5] PIXELCLOCKGATED bit to 0x1.
The LCD output can be configured in progressive output or interlace output. The selection is done by writing into the DISPC_CONFIGo[22] OUTPUTMODEENABLE bit. The reset value is 0x0, which means progressive mode. When progressive mode is selected, the FID signal associated to the LCD output is driven low (INACTIVE state). The selection can be changed only if the corresponding LCD output is disabled. The configuration is independent for each LCD output.
When in interlaced mode, the DISPC_CONFIGo[23] FIDFIRST bit indicates which field is output first: