Samsung S5PC100, User Manual

Page: 1018 / 1863

DISPLAY CONTROLLER S5PC100 USER’S MANUAL (REV1.0)
9.1-4
3 FUNCTIONAL DESCRIPTION
3.1 BRIEF OF THE SUB-BLOCK
The display controller consists of a VSFR, VDMA, VPRCS, VTIME, and video clock generator. The VSFR has 107
programmable register sets and five 256x32-palette memories. This is used to configure the display controller.
The VDMA is a dedicated display DMA, which transfers the video data in frame memory to VPRCS. By using this
special DMA, displays the video data on the screen without CPU intervention. The VPRCS receives the video data
from VDMA and sends the video data through the data ports (RGB_VD, VEN_VD, V656_VD or SYS_VD ) to the
display device (LCD) after changing them into a suitable data format, for example 8-bit per pixel mode (8 BPP
Mode) or 16-bit per pixel mode (16 BPP Mode). The VTIME consists of programmable logic to support the
variable requirement of interface timing and rates commonly found in different LCD drivers. The VTIME block
generates RGB_VSYNC, RGB_HSYNC, RGB_VCLK, RGB_VDEN, VEN_VSYNC, VEN_HSYNC, VEN_FIELD,
VEN_HREF, V601CLK, V656CLK and SYS_CS0, SYS_CS1, SYS_WE and so on.
3.2 DATA FLOW
FIFO is present in the VDMA. If FIFO is empty or partially empty, VDMA requests data fetching from the frame
memory based on the burst memory transfer mode
. The data transfer rate determines size of FIFO. The display
controller has five FIFOs because it needs to support the overlay window display mode. Use one FIFO for one
screen display mode. VPRCS fetches data through FIFO, which has a blending, scheduling function for the final
image data. VPRCS supports overlay function. This enables to overlay any image up to 5 window images whose
is smaller or same size can be blended with main window image with programmable alpha blending or color
(chroma) key function. Figure 9.1-2 shows the data flow from system bus to the output buffer. VDMA has 5 DMA
channels and 3 Local Input I/F. Color Space Conversion (CSC) block changes YCbCr (Local input only) data to
RGB data for the blending operation. Alpha values written in SFR determine the level of blending. Data from
Output buffer appears to the Video Data Port.