Specifications

Color LCD Controller (CLCDC)
ARM DDI 0287B Copyright © 2004, 2006 ARM Limited. All rights reserved. 5-7
5.3 Hardware cursor extension to PL110
The PL110 controller in the ARM926EJ-S Development Chip has been extended to
include a hardware cursor extension.
5.3.1 Hardware cursor extension
Before the hardware cursor was introduced, moving the cursor required software to:
• save an image of the area under the next cursor position
• update the area with the cursor image
• repair the last cursor position with a previously saved image.
With a cursor size of 64x64 and 24-bit color, each cursor move involved reading and
writing approximately 75KB of data. The hardware cursor, however, provides a
completely separate image buffer for the cursor, and superimposes the cursor image on
the LCD output stream at the current cursor (X,Y) coordinate. To move the hardware
cursor, the software driver supplies a new cursor coordinate. Because the frame buffer
requires no modification, this significantly reduces the software overhead.
The cursor image is held in the CLCDC in a 256x32-bit dual-port RAM. The contents
are programmed through the CLCDC AMBA AHB slave interface.
Figure 5-3 shows a block diagram of the hardware cursor.
Figure 5-3 Hardware cursor block diagram
Registers
CursorCtrl
HWDATA[31:0]
HADDR[10:2]
Bus control
HRDATA[31:0]
HADDR[9:2]
Register information
InterruptReq
Palette0,1
IA DDR[7:0]
IDATA[31:0] Unpack
HBP[7:0], VBP[7:0]
LPP[9:0], PPL[7:2]
RGBMux
InvertRGB
Frame(r,g,b)[7:0]
Palette1(r,g,b)[7:0]
Palette0(r,g,b)[7:0]
HClkDomain LCDClkDomain
ClkSynch
CrsrImageRAM