Does the data length for USB3.0 pipe transfers need to be mod4

FrontPanel
1

Hi,

Does the data length for USB3.0 pipe transfers need to be mod4 (multiples of 4 bytes)?

Is this true for both the C API and the XML Component functions too?

Thanks,

2

Found the answer in the FrontPanel API Reference installed from the CD. The online version (OK Website) did not seem to have this information.

The answer is yes, multiples of 4 bytes.

"Length is specified in bytes and restrictions are device-dependent, but generally must be an even multiple of the block size. Further,

USB 2.0: Multiple of 2 [2…16777214].
USB 3.0: Multiple of 4 [4…16777212].
PCIe: Multiple of 8 [8…16777208]. "

3

[QUOTE=pavan;3870]Found the answer in the FrontPanel API Reference installed from the CD. The online version (OK Website) did not seem to have this information.

The answer is yes, multiples of 4 bytes.

"Length is specified in bytes and restrictions are device-dependent, but generally must be an even multiple of the block size. Further,

USB 2.0: Multiple of 2 [2…16777214].
USB 3.0: Multiple of 4 [4…16777212].
PCIe: Multiple of 8 [8…16777208]. "[/QUOTE]

I found that the length of pipe of USB3.0 must be multiple of 16; blocksize of BTpipe is one of [16,32,64,128,256,1024,4096,16384].