Undocumented phenomenon?

Thread View: comp.sys.transputer

1 messages

[T] Back to Threads [V] Tree View [G] Group Articles

1 total messages Started by Victor Todd Norman Tue, 27 Mar 1990 21:42

#523

Author: Victor Todd Norman
Date: Tue, 27 Mar 1990 21:42

17 lines
1110 bytes

I have noticed something that I don't believe appears anywhere in any
documentation.  Here's the situation:

I have one high priority process running on my T414B.  This process
looks at the special "register save area" (see p. 79 of Compiler
Writers' Guide), and sees NotProcess.p (0x80000000) in WdescIntSaveLoc
(thus, no low priority process was interrupted).  Then, the process
executes an IN instruction, and then looks again at WdescIntSaveLoc,
and now the value has been changed to 0x80000001 (the low bit has been
set).

I supposed there is a good reason for this?, or is my hardware acting funny...

I have noticed that this only happens if the process doing the IN (or
OUT) is running at high priority.

Victor Norman

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads