In UDP mode of keil network stack, when we use BSD API, is there any crc check in UDP packets send/receive?
if yes, in STM32F4 series, use hardware crc block or software ?
The basic UDP packet doesn't contain any CRC. It contains a checksum.
Correct it's not a CRC, a sum is not a polynomial remainder. The Ethernet packets, if you use that interface, have a 32-bit CRC generated by the MAC