68300

Any self-respecting compiler or assembler should issue an error
message if one tries to fit into a word an address bigger than
that (notice that the 68K family treats .w absolute addresses as signed
integers, i.e. the physical address is the sign-extended value
of the .w).

 This sounds to me more like an attempt to access non-exsitant
memory - which gets caught by the bus monitor after hanging for
a while and is BERR-ed.

 At any rate, BERR has little or nothing to do with 24 vs. 32
address bits as long as you attempt to access existing hardware
resources in your system.

Dimiter

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Dimiter Popoff
http://transgalactic.freeyellow.com




-----Original Message-----
From: iomer@...
Sent: Tuesday, March 04, 2003 4:39 AM
To: 68300@yahoogroups.com
Subject: [68300] Theoretical questions


Could somebody explain to me why a Bus error exception shall occur 
when commands like
           MOVE.L (_BlaBla),A1   or
           ADD.L  A2,(_Blabla)
Well it seems the problem is the indirect access to the var. In 
cpu32rm there is no word about indirect access from memory site 
I suspect the problem is caused by the address bus being 24 bit long 
while the address registers are 32 bit 
Yet I could use a better explanation