Hi Gang,

I am working with a PIC18F4585, I want to use the Parallel Slave Port.

So far I have found:

You can not initialize the PSP correctly if the CS pin is active. (Low)
(It causes the PSPIF to be set even though there is no WR or RD, when you
set the PSPMODE bit.)

O.K. that's fair, but it violates the explanation of how the PSP works.

"A write to the PSP occurs when BOTH the CS and WR lines are first detected
Low and ends when either are detected high.  The PSPIF and IBF flag bits are
both set when the write ends."

After that, the PSP will NOT honor another H>L on CS and WR with an
interrupt.
As I said in the last posting, it sets the flag, but the hardware handler
Ignores the flag!  And it messes up it's internal logic so the next write
Signals IBOV (Overflow.)


Well, correcting the CS (now inactive) while I initialize the device,
I can now get interrupts when I write to the PSP.  Hurrah!
But reading PORTD get me nothing. (0X00)
I see (Scope) the data at the pins, I see the CS and WR, all correctly
timed.
(Booo!)

I have TRISD set to (0xFF), I wonder... (I'll try after lunch...)

Tom

  *
  |  __O    Thomas C. Sefranek  WA1RHP@ARRL.NET
  |_-\<,_   Amateur Radio Operator: WA1RHP
  (*)/ (*)  Bicycle mobile on 145.41MHz PL74.4
 
ARRL Instructor, Technical Specialist, VE Contact.
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