ALLIED Vision Technologies Guppy F-503 - Manual (Page 283)

Configuration of the camera
GUPPY Technical Manual V7.1.0
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GPDATA_BUFFER
GPDATA_BUFFER is a register that regulates the exchange of data between
camera and host for programming the LUT.
GPDATA_INFO Buffer size query
GPDATA_BUFFER Indicates the actual storage range.
Little endian vs. big endian byte order
• Read/WriteBlock accesses to GPDATA_BUFFER are recommended, to read
or write more than 4 byte data. This increases the transfer speed com-
pared to accessing every single quadlet.
• The big endian byte order of the 1394 bus is unlike the little endian
byte order of common operating systems (Intel PC). Each quadlet of the
local buffer, containing the LUT data or shading image for instance, has
to be swapped bytewise from little endian byte order to big endian byte
order before writing on the bus.
Register Name Field Bit Description
0xF1000FFC GPDATA_INFO --- [0..15] Reserved
BufferSize [16..31] Size of GPDATA_BUFFER
(byte)
0xF1001000
…
0xF10017FC
GPDATA_BUFFER
Table 134: Advanced register: GPData buffer register
Note

• Read the BufferSize before using.
• GPDATA_BUFFER can be used by only one function at a
time.
Bit depth little endian big endian Description
8 bit L0 L1 L2 L3  L3 L2 L1 L0 L: low byte
H: high byte 16 bit L0 H0 L1 H1  H1 L1 H0 L0
Table 135: Swapped first quadlet at address offset 0