Re: 25 microseconds?

Yes, I am talking about interrupt driven PIO.
Instead of giving my opinions about what you should do in an ISR,
let me describe what Microsoft actually does in one of their own ISR's.
In SERIAL.SYS, the ISR typically runs between 50 to 55 microseconds.
I think SERIAL.SYS is a well written driver that understands the need
to
drain the 16 byte FIFO inside the ISR to maintain reasonable
throughput.
But the Microsoft driver violates the new logo requirement.

I really don't think 50 or even 100 microseconds is excessive for an
ISR.
I plan to send feedback on the draft logo specification, I just hope
I'm not
the only one. I don't see any messages from other Super I/O vendors.

.

Relevant Pages

  • Re: 25 microseconds?
    ... points out how unrealistic a hard 25 microsecond time limit for the ISR is. ... let me describe what Microsoft actually does in one of their own ISR's. ... I think SERIAL.SYS is a well written driver that understands the need ... Mark Roddy DDK MVP ...
    (microsoft.public.development.device.drivers)
  • Re: 25 microseconds?
    ... > let me describe what Microsoft actually does in one of their own ISR's. ... the ISR typically runs between 50 to 55 microseconds. ... > I think SERIAL.SYS is a well written driver that understands the need ... > I plan to send feedback on the draft logo specification, ...
    (microsoft.public.development.device.drivers)
  • Re: 25 microseconds?
    ... the ISR typically runs between 50 to 55 microseconds. ... But the Microsoft driver violates the new logo requirement. ... I plan to send feedback on the draft logo specification, ...
    (microsoft.public.development.device.drivers)
  • Re: 25 microseconds?
    ... let me describe what Microsoft actually does in one of their own ISR's. ... the ISR typically runs between 50 to 55 microseconds. ... I think SERIAL.SYS is a well written driver that understands the need ... I plan to send feedback on the draft logo specification, ...
    (microsoft.public.development.device.drivers)
  • Re: 25 microseconds?
    ... You would think that a company the size of Microsoft with the resources it has available would have fixed it up a long time ago. ... the ISR has to drain the fifo and then queue the dpc. ... I think SERIAL.SYS is a well written driver that understands the need ...
    (microsoft.public.development.device.drivers)
Loading