LH79524/LH79525 User’s Guide
Color Liquid Crystal Display Controller
Version 1.0
4-27
4.5.3.5 Lower Panel Frame Buffer Base Address Register (LPBASE)
The LPBASE Register is one of two Color LCD DMA Base Address Registers (the other is
UPBASE, described in Section 4.5.3.4). Together with UPBASE, this Read/Write register
programs the base address of the frame buffer.
LPBASE is used for the lower panel of dual-panel STN displays. UPBASE must be initial-
ized (and LPBASE for dual panels) before enabling the CLCDC. Optionally, the value can
be changed mid-frame to allow double-buffered video displays to be created. These reg-
isters are copied to the corresponding current registers at each LCD vertical synchroniza-
tion. This event causes the BUI bit and an optional interrupt to be generated. The BUI bit
indicates that it is safe to update both the UPBASE and LPBASE Registers. The interrupt
can be used to reprogram the base address when generating double-buffered video.
Table 4-22. LPBASE Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
LCDLPBASE
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
LCDLPBASE
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RO
RO
ADDR
0xFF 0x14
Table 4-23. LPBASE Register Fields
BIT
NAME
DESCRIPTION
31:2 LCDLPBASE
LCD Lower Panel Base Address
This is the start address of the
lower panel frame data in memory and is word-aligned.
1:0
///
Reserved
Reading returns 0. Write the reset value.