GD32W51x User Manual
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signal (DCI_Hs or DCI_Vs). DCI uses embedded sync detection module to extract
synchronization information from pixel data, and then recover horizontal and vertical
synchronization signals.
The window timing module performs image cutting function. This module calculates a pixel’s
position using synchronization signals either from DCI interface or embedded sync detection
module and then decides whether this pixel data needs to be received according to the
configuration of DCI_CWSPOS and DCI_CWSZ registers.
DCI uses a 4 word (32-bit) FIFO to buffer the received pixel data. If DMA mode is enabled,
the DMA interface asserts a DMA request every time the FIFO is not empty. Control register
provides register interface between DCI and software.
25.4.
Signal description
Table 25-1. PINs used
by DCI
Direction
Nam e
Width
Description
Input
DCI_PixClk
1
DCI Pixel Clock
Input
DCI_PixData
14
DCI Pixel Data
Input
DCI_Hs
1
DCI Horizontal Synchronization
Input
DCI_Vs
1
DCI Vertical Synchronization
25.5.
Function overview
25.5.1.
DCI hardware synchronization mode
In DCI hardware synchronization mode (ESM bit in DCI_CTL register is 0), DCI_Hs and
DCI_Vs signals are used to indicate the start of a line and a frame. DCI captures pixel data
from DCI_PixData[13:0] at rising or falling edge of DCI_PixClk (clock polarity is configured by
CKS bit in DCI_CTL).
Figure 25-2. Hardware synchronization mode
Line 0
Line 1
Line 2
Line N-1
DCI_PixClk
DCI_Vs
DCI_Hs
DCI_PixData[13:0]
Frame
Line
The above figure assumes that the polarities of both DCI_Hs and DCI_Vs are high during
blanking period, so the data on DCI_PixData lines is only valid when both DCI_Hs and
DCI_Vs are low.