This message is from the T13 list server.
This message is from the T13 list server.
I have some questions about the new proposal
"e04155r0 - DRQ=0 When ERR=1 Feature and
Allocation Identify Device Words Proposal"
http://t13.org/docs2004/e041559r0-DRQ-ERR-and-ID-Words.pdf
Why do we need this ?
What problem does it really solve ?
Why should we define a feature that allows a BAD DEVICE to do something
stupid instead of fixing the bad device ?
I agree entirely with Mr. Hatfield. What "problem" is this trying to solve?
I've never seen BSY=0 DRQ=1 ERR=1 status be a problem. It is equivalent to BSY=0 DRQ=0 ERR=1. Either way a "well designed" host will issue a Soft Reset (SRST) and probably retry the failing command.
DRQ with ERR means ERR?
Eh? That's a consensus opinion?
I think I remember I once wrote software that took DRQ with ERR to mean DRQ ... perhaps I saw device hardware that worked that way, e.g. by rudely neglecting to clear ERR until just before clearing the final BSY and DRQ of a command.
When & were did we begin forbidding the interpretation that DRQ with ERR means DRQ?
And if DRQ with ERR means ERR, why then SRST? SRST in reaction to an unexpected DRQ I understand - but in reaction to an unexpected ERR?
Help, I'm lost ... though curious ... Pat LaVarre http://ide-byte-counting.blog-city.com/
