Motorola MC68VZ328 - Manual (Page 132)

8-4 MC68VZ328 User’s Manual
LCD Controller Operation
Figure 8-2. LCD Interface Timing for 4-, 2-, and 1-Bit Data Widths
8.2.2 Controlling the Display
The LCD controller is designed to drive single-screen monochrome STN LCD panels with up to 640 × 512
pixels in black-and-white display and 320 × 240 pixels in gray level display. A screen size larger than
320 × 240 for gray level display may cause flickering due to a slow refresh rate. The best efficiency is
achieved when the screen width is a multiple of the DMA controller’s 16-bit bus width.
8.2.2.1 Format of the LCD Screen
The screen width and height of the LCD panel are programmable through software. Figure 8-3 on page 8-5
illustrates the relationship between the portion of a large graphics file displayed on the screen and the
actual page. The units in the figure are measured in pixel counts.
LD1 [0,0] [2,0] [4,0]
LD0 [1,0] [3,0] [5,0]
[m-4,0] [m-2,0]
[m-3,0] [m-1,0]
[38,0] [40,0]
[39,0] [41,0]
2-bit LCD data bus (PBSIZ = 01)
LCLK
1 2 3 m m-1 20 21
LLP
LFLM
LLP
LINE 1 LINE 2 LINE 3 LINE 4 LINE n LINE 1
LD0 [0,0] [1,0] [2,0] [m-2,0] [m-1,0] [19,0] [20,0]
1- bit LCD data bus (PBSIZ = 00)
LD0
[3,0] [7,0] [11,0]
LD1 [2,0] [6,0] [10,0]
LD2 [1,0] [5,0] [9,0]
LD3 [0,0] [4,0] [8,0]
[m-5,0] [m-1,0]
[m-6,0] [m-2,0]
[m-7,0] [m-3,0]
[m-8,0] [m-4,0]
[79,0] [83,0]
[78,0] [82,0]
[77,0] [81,0]
[76,0] [80,0]
4-bit LCD data bus (PBSIZ = 10)