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I don't know, I wasn't the original designer.  Perhaps software wasn't
expected to poll on the device status register, but should instead be
polling on the ACT bit in the host bus-master device register, or just
waiting for the interrupt.  So, it shouldn't have mattered,
performance-wise.

T.E.

-----Original Message-----
From: Hale Landis [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 10, 2002 2:22 PM
To: [EMAIL PROTECTED]
Subject: RE: RE: [t13] UDMA Bursts - Pause versus Termination

...

But why do this? From day one of this interface we know that during
the execution of a DMA data transfer command a device should have
status of BSY=1 (yes, some devices have status of BSY=0 DRQ=1 but
that doesn't matter, either status tells the host the device is
busy). So why should a host adapter terminate a DMA data burst in
progress when the host does a read of one of the device registers?
Why not just tell return fake data of 80H and let the DMA data burst
continue uninterrupted?

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