Maximum Value of xferdata() Length Parameter - KBA84124
Translation - Japanese:
What is the maximum value of the xferdata() length parameter in CyAPI.lib/CyUSB.dll?
You can calculate the maximum value of the xferdata() length parameter or any other parameter in CyAPI.lib and CyUSB.dll by referring to the corresponding programmer’s reference guide. However, the maximum value of the parameter changes if it is restricted by USB protocol or the OS environment. In CyAPI.lib the length of transfer is defined as LONG and in CyUSB.dll it is defined as int, which means it has a size of 4 bytes. The maximum value is 0x7FFFFFFF.
Install FX3 SDK to get the programmer’s reference guides. The reference guide for CyAPI.lib is available at C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\SuiteUSB\CyAPI.pdf and the reference guide for CyUSB.dll is available at C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\SuiteUSB\CyUSB.NET.pdf.
Note Though these parameters are not restricted, large transfers are not recommended.