SPRUIL1D May 2019 – December 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1
Non Burst Event Mode uses the Short packet and Long packet structures to track the DPI interface timing without accurate reconstruction of sync pulse widths, so a single Sync Event is substituted. Figure 1-1 illustrates the packet sequence for a single frame.
The DSITX controller registers for this mode are used to generate the exact number of bytes required for each horizontal.
line based on the DPI line configuration and the BPP for the colour pixel data. The packet structure for each type of line during the frame is shown in Figure 12-1107:
The DSI short packets and packet headers that are inserted by the controller must be accounted for:
Finally, for lines with no active data, the controller will use either:
Program the DSI horizontal size registers as follows:
burst_mode = 0 and sync_pulse_active = sync_pulse_horizontal = 0;
Note: (DPI_HACT × bpp/32) must be an integer. Total Line Length = div_roundup((HLINE × bpp/8), num of lanes).
(BLKLINE_EVENT_PCK) bytes} = (HLINE × bpp/8 ) - 10
(REG_LINE_DURATION) txbyteclks} = Total Line Length - div_roundup(8, number of lanes)
(VERT_BLANKING_DURATION) txbyteclks} = Total Line Length - div_roundup(4, number of lanes)
For example: a DPI with HSA = 12, HBP = 12, HACT = 1920, HFP = 24 and 16bpp will be 1968 pixel clocks for each horizontal line. This give each DSI HLINE of 3936 bytes.
HSA = 0
HBP = ((12 + 12) × 16/8) -12 = 24
HACT = (1920 ×16/8) = 3840
HFP = (24 ×16/8) -6 = 42
Total Line = div_roundup((12 + 12+1920 + 24) × 16/8, 4) = 984
BLKLINE_EVENT_PCK = (HLINE × bpp/8) – 10 = 981
REG_LINE_DURATION = 984 – div_roundup(8, 4) = 982
VERT_BLANKING_DURATION = 984 – div_roundup(4, 4) = 983
Confirming the calculation for each line:
VSS = VSSPkt + BLK_LINE_EVENT_PCKPkt = 4 + (4 + 3926 + 2) = 3936
VSALine = HSSPkt + BLK_LINE_EVENT_PCKPkt = 4 + (4 + 3926 + 2) = 3936
VSE = VSEPkt + BLK_LINE_EVENT_PCKPkt = 4 + (4 + 3926 + 2) = 3936
VACT = HSSPkt + HBPPkt + HACTPkt + HFPPkt = 4 + (4 + 24 + 2) + (4 + 3840 +2) + (4 + 42 + 2) = 3936
VFP = HSSPkt + BLK_LINE_EVENT_PCKPkt = 4 + (4 + 3926 +2) = 3936
VFPLast = HSSPkt + VERT_BLANKING_DURATION = 4 + (983 × 4) = 3936