Intel® PXA255 Processor Developer’s Manual
7-37
LCD Controller
7.6.6
LCD DMA Frame Branch Registers (FBRx)
FBRx, one for each DMA channel, shown in
Table 7-11
, contain the addresses, aligned on a 4-byte
boundary, of the descriptors to branch to.
When BRA is set, the Frame Descriptor Address Register is ignored. The next descriptor is fetched
from the address in FBRx[31:4], regardless of whether frame data or palette RAM data is being
processed. Setting BINT to one forces the DMAC to set the Branch Status interrupt bit (BS) in the
LCD Controller Status Register after fetching the branched-to descriptor. BRA is automatically
cleared by hardware when the branch is taken.
Note:
In dual-panel mode, both FBR0 and FBR1 must be written in order to branch properly.
These are read/write registers. Ignore reads from reserved bits. Write zeros to reserved bits.
Table 7-11. FBRx Bit Definitions
Physical Address
channel 0: 0x4400_0020
channel 1: 0x4400_0024
LCD DMA Frame Branch Registers
LCD Controller
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
Frame Branch Address
re
ser
v
ed
BI
N
T
BR
A
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0 X X 0
0
Bits
Name
Description
31:4
Frame
Branch
Address
Frame Branch Address:
Address of the descriptor for the branched-to frame.
3:2
—
reserved
1
BINT
Branch Interrupt:
0 = Do not set the BS interrupt bit in register LCSR after the branched-to descriptor is
loaded.
1 = Set the BS interrupt bit in register LCSR after the branched-to descriptor is loaded.
0
BRA
Branch:
0 = Do not branch after finishing the current frame.
1 = Branch after finishing the current frame. The next descriptor will be fetched from the
Frame Branch Address. BRA is automatically cleared after loading the new descriptor.
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......