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LH75400/01/10/11 (Preliminary) User’s Guide
Color Liquid Crystal Display Controller
7/15/03
13-15
13.3.2.5 Upper Panel Frame Buffer Base Address Register
The UPBASE Register is one of two Color LCD DMA Base Address Registers (the other
is LPBASE). Together with LPBASE, this Read/Write register programs the base address
of the frame buffer.
UPBase is used for:
• TFT displays
• Single-panel STN displays
• The upper panel of dual-panel STN displays.
UPBase (and LPBase for dual panels) must be initialized before enabling the CLCDC.
Optionally, the value can be changed mid-frame to allow double-buffered video displays to
be created. These registers are copied to the corresponding current registers at each LCD
vertical synchronization. This event causes the LNBU bit and an optional interrupt to be
generated. The LNBU 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 13-16. UPBASE Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
LCDUPBASE
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
LCDUPBASE
///
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
R
R
ADDR
0xFF 0x10
Table 13-17. UPBASE Register Definitions
BIT
NAME
DESCRIPTION
31:2 LCDUPBASE
LCD Upper Panel Base Address
Specifies the starting address of the
upper-panel frame data in memory and is word aligned.
1:0
///
Reserved
Writing to these bits has no effect. Reading returns 0.