PXD20RM Datasheet, PDF (1567/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Table 47-19.
Color BC LUT
Component Offset
Y
0x000
00
BC0_Y
0x0FC BC252_Y
U
0x100
BC0_U
0x1FC BC252_U
V
0x200
BC0_V
0x2FC BC252_V
Local Address [1:0]
01
BC1_Y
......
BC253_Y
BC1_U
......
BC253_U
BC1_V
......
BC253_V
10
BC2_Y
BC254_Y
BC2_U
BC254_U
BC2_V
BC254_V
11
BC3_Y
BC255_Y
BC3_U
BC255_U
BC3_V
BC255_V
Figure 47-18. B/C Adjust Look-up-table Format
Two registers are provided to program the look-up-table, they are LUT_ADDR (47.2.3.14/47-14) and
LUT_DATA (47.2.3.15/47-15). LUT_ADDR is the current address pointer, which always points to the
current table offset to be programmed. It can be set by software, and it increases (by 4) automatically when
each word is written to the table, and it falls back to 0x000 if the current value is 0x2FC and the last word
is written to the table. LUT_DATA is the table data entry, data written to this register will be stored into
the table, to the address pointed to by LUT_ADDR. This register shall only be written by 4-byte word.
With combination of these two registers user can program the B/C look-up-table conveniently, either
program the whole table, or reprogram the table for one color component only, or even change one single
arbitrary word in the table.
The B/C adjust can be enabled/disabled by software via the BC_EN bit in the STATUS_CONFIG register
(47.2.3.1/47-5).
47.3.6 YUV to RGB Conversion
The YUV2RGB block (5) is used to convert YUV (4:2:2 or 4:4:4) to RGB (888 or 565). The coefficients
of the YUV to RGB conversion matrix are programmed via four registers (47.2.3.2/47-7, 47.2.3.3/47-8,
47.2.3.4/47-9, 47.2.3.5/47-9). When the input is YUV 4:2:2, it’s interpolated to YUV 4:4:4 first.
47.3.7 Round and Dither
In RGB565 output mode, when pixel data is converted from RGB888 to RGB565 the image is anamorphic
more or less, because of losing color information conveyed by the least significant two or three bits of the
original color components, which are dropped. VIU2 block provides two simple algorithms, round and
dither, to compensate this color information loss.
Freescale Semiconductor
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
47-19