troy99xx
Newbie level 6
hello:
ref : polynomial CRC32 for 802.3 (not pure Ethernet, but uses same polynomial )
Not very familiar with CRC but I have read a lot of information on the web.
I have seen places where you you can use online tools to generate VHDL code base on on particular polynomial and data width.
I am confused how to implement in VHDL a running CRC check on incoming parallel data.
For example, on a 128Byte field of data I need to implement a CRC checker on a 64-bit parallel bus (meaning those 128Kb are captured 64-bits at the time) . The data frame includes a CRC field.
1) If I use one of those parallel CRC implementations, do I need to feed the 64-bits on each clock cycle into the CRC generator until all 128Kbytes are completed? This is part I am confused, how is the total CRC for 128kbyte package calculated ?
2) If the data is less than 128kb, do I need to fill zeros to get the correct CRC?
3) If anyone can post some VHDL sample code , it be will helpful
I have read all posts in the site related to CRC but I couldn't find the answer
any help is appreciated
thank you
ref : polynomial CRC32 for 802.3 (not pure Ethernet, but uses same polynomial )
Not very familiar with CRC but I have read a lot of information on the web.
I have seen places where you you can use online tools to generate VHDL code base on on particular polynomial and data width.
I am confused how to implement in VHDL a running CRC check on incoming parallel data.
For example, on a 128Byte field of data I need to implement a CRC checker on a 64-bit parallel bus (meaning those 128Kb are captured 64-bits at the time) . The data frame includes a CRC field.
1) If I use one of those parallel CRC implementations, do I need to feed the 64-bits on each clock cycle into the CRC generator until all 128Kbytes are completed? This is part I am confused, how is the total CRC for 128kbyte package calculated ?
2) If the data is less than 128kb, do I need to fill zeros to get the correct CRC?
3) If anyone can post some VHDL sample code , it be will helpful
I have read all posts in the site related to CRC but I couldn't find the answer
any help is appreciated
thank you