Instruction manual

Guppy PRO Technical ManualV4.1.0
238
Configuration of the camera
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 compared to
accessing every single quadlet.
• The big endian byte order of the 1394 bus is unlike the little endian byte
order of common Intel PCs. Each quadlet of the local buffer, containing the
LUT data for instance, has to be swapped bytewise from little endian byte
order to big endian byte order before writing on the bus.
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 155: Swapped first quadlet at address offset 0