Philips Semiconductors
Product specification
Multimedia bridge, high performance
Scaler and PCI circuit (SPCI)
SAA7146A
Table 62 YUV 4 : 2 : 2 format
PACKING WITHIN 32-BIT Dword
BIT 23 TO BIT 16 BIT 15 TO BIT 8
V0 Y0
BIT 31 TO BIT 24
BIT 7 TO BIT 0
Y1
U0
Table 63 YUV 4 : 1 : 1 format
PACKING WITHIN 32-BIT Dword
BUS CYCLE
BIT 31 TO BIT 24
BIT 23 TO BIT 16
BIT 15 TO BIT 8
BIT 7 TO BIT 0
1
2
3
Y1
Y3
Y7
V0
V4
V6
Y0
Y2
Y5
U0
U4
Y4
The following formats are planar YUV formats and use the three video FIFOs and three video DMA Channels 1, 2 and 3.
The byte phase of the first sample each line is defined by the 2 LSBs of every DMA base.
• YUV 4 : 4 : 4; U and V sampled with every Y sample
• YUV 4 : 2 : 2; U and V sampled co-sided with first Y sample (of 2 samples in-line)
• YUV 4 : 2 : 0; MPEG U and V sampled at upper left sample of 4 sample in square (2 × 2)
• YUV-9 video; U and V sampled at selected sample of 16 samples in-square (4 × 4)
• YUV1; YUYV, YUYV...
• YUV2; YYUU, YYVV...
7.11.1.3 8-bit formats
• Y8G; Only Y or inverted Y
• α8; 8-bit alpha information, to be master-read through FIFO 2 and merged into RGB-24 with alpha.
There are two pseudo CLUT formats, which derives its bits from RGB-24 or YUV-24 by truncation, or by error diffusion
dither. The byte phase of the first sample each field is defined by 2 LSBs of DMA base.
• RGB-8 (3 : 3 : 2); Red has 3 bits, Green has 3 bits, Blue has 2 bits
• YUV8 (4 : 2 : 2); Y has 4 bits, U has 2 bits, V has 2 bits. Y = 0 doesn’t exist, to handle 16-bit colour formats for pseudo
CLUT. After dithering, Ymin = 1.
All 8-bit formats are packed formats, 4 samples go into one Dword. The byte phase of the first sample of each line is
defined by the 2 LSBs of the DMA base. All except α8 use FIFO 1.
Table 64 8-bit formats
PACKING WITHIN 32-BIT Dword
BIT 31 TO BIT 24
BIT 23 TO BIT 16
BIT 15 TO BIT 8
BIT 7 TO BIT 0
pixel3
pixel2
pixel1
pixel0
1998 Apr 09
82
NXP [ NXP ]
