zr36067 ETC-unknow, zr36067 Datasheet - Page 20

• Manufacturer Part Number: zr36067
• Description: Av Pci Controller
• Manufacturer: ETC-unknow

AV PCI CONTROLLER
Table 7: 24-bit Unpacked Pixel Format
8.0 GRAPHICS OVERLAY
The ZR36067’s Video DMA Controller is capable of masking off
(i.e., not transmitting) pixels that are marked by ‘0’ in a masking
map prepared and maintained by the driver software. The
masking feature, referred to as overlay or clipping, is turned on
by setting the OvlEnable parameter to ‘1’. As long as OvlEna-
ble=’0’, all pixels within the selected portion of the image are
transferred to destination. The masking map is a one bit deep
map of the video rectangle. Its location in system memory is
defined by a pair of base addresses (one for each field - Mask-
TopBase, MaskBotBase), and an inter-line stride (MaskStride).
The width of the map must be doubleword aligned. Thus, the line
size is:
9.0 JPEG CODE TRANSFER
The data flow direction depends on the JPEG mode of opera-
tion. In Motion Video and Still Image Compression, the code is
transferred from the CODE bus to the system memory. In Motion
Video and Still Image Decompression, the code is transferred
from the system memory to the CODE bus.
The compressed data in system memory is structured within
code buffers. Each code buffer may contain a compressed field
or frame (two fields) as specified by a user-configurable bit.
The ZR36067 supports four code buffers, defined dynamically in
a dedicated table, the Code Buffer Table, in the system memory.
Before starting a new JPEG process, the host must load the
p h y s i c a l a d d r e s s o f t h e c o d e b u f f e r t a b l e i n t o t h e
I_STAT_COM_PTR register of the ZR36067.
The actual memory allocated to each code buffer by the operat-
ing system may be fragmented. The content of each entry in the
code buffer table is a pointer to a secondary Fragment Table.
The fragment table contains the pointers to the allocated
memory chunks.
Little Endian
Gib Endian
Endian-ness
int((VidWinWid+31) >> 5)
B7...0
0x0
31...24
R7...0
G7...0
23...16
Bits
G7...0
R7...0
15...8
B7...0
0x0
7...0
20
In the 24-bit packed format the first active pixel in a line is always
packed as indicated in the “First” row of Table 8. From then on
the byte organization is as described by the table.
Table 8: 24-bit Packed Pixel Format
and the number of lines in the map is:
In order to match the 0/1 values of the map to their correspond-
ing pixels in the video rectangle, the map must follow the format
given in Table 9.
Table 9: Bit, Byte and Doubleword Organization of
the Masking Map
Figure 9 provides a graphical description of the data structure in
the system memory.
9.1 The Code Buffer Table
The Code Buffer Table consists of four STAT_COM (“status or
command”) entries, one for each code buffer. The interpretation
of each STAT_COM entry is determined by its l.s. bit, the
STAT_BIT. If STAT_BIT=’0’, the content of the entry is the “com-
First
Second
Third
DWORD
Byte
Bit
Pixel index in line
Figure 9. JPEG Code Data Structure In System Memory
2*VidWinHt, if DispMod==0, or VidWinHt, if DispMod==1.
Bus Cycle
I_STAT_COM_PTR
LENGTH_n-1
Fragment Table
ADDRESS_n-1
LENGTH_0
LENGTH_1
ADDRESS_0
ADDRESS_1
F=Final
F
F
F
B17...0
G27...0
R37...0
39...32
7....0
31...24
...1
...0
31...24
31...24
R07...0
B27...0
G37...0
3
Fragment_n-1
23...16
Fragment_0
Fragment_1
23...16
23...16
Bits
2
G07...0
R17...0
B37...0
15...8
0
15... 8
15...8
Code Buffer Table
1
STAT_COM0
STAT_COM1
STAT_COM2
STAT_COM3
B07...0
G17...0
R27...0
7...0
7...0
7...0
0