Forum Discussion
Altera_Forum
Honored Contributor
Honored Contributoravalon mm byte enable
In the project we are currently working on, we want to read and write pixels to external DDR SDRAM. We need to be able to use byte-mask / byte-enable bits to not overwrite some previously writt...
Altera_ForumHonored Contributor
Honored ContributorSo here are my thoughts:
1 - I never noticed this before, I wonder if it's a recent addition to the documentation. 2 - --- Quote Start --- I can't use the byte mask 1100, according to the above. --- Quote End --- Yes you can. According to the table, the only combinations you couldn't use would be: 0111 1011 1101 1110 0101 0110 1001 1010 3 - Have you tried it? Honestly I think I'd just try it anyway and see what happens. It may just work. It seems like if you always present a word address, the byte enables would be taken as they are given. I'd be surprised if there is actually some logic in the interconnect fabric that manipulates them. Try it. 4 - It does seem a little odd to me that you would be writing random bytes within a word. Especially pixel data. Are you sure you can't just buffer up multiple pixels and perform a single write. I guess I just don't know enough about what your trying to do to understand the usefulness. Jake
