Memory Tests
Word Tests
Word (16 bit) wide
tests
are
executed on main memory.
There
are
two
types
of word wide
tests
used. Tests on
the
upper
16K bytes
and
all peripherals always use
the
slower, walking ones
and
zeros, test.
The
rest of main memory may use
either
the
slow test,
or
a faster "address in
mernory" test.
Byte
(8
bit) wide
tests
use
the
walking ones/zeros test.
This
test
is used on any peripheral
that
has less
than
full word wide memory (e.g.
alpha
display controller memory,
and
some graphics
memory).
These
tests
are faster
than
the
same ones used with
the
Models 310
and
320. As
the
MC68020
ICACHE
is enabled,
there
is a noticeable speed improvement.
The
same messages are used for reporting all memory failures,
but
they are
interpreted
slightly
differently for word
and
byte
memory tests.
For word wide memory
test
errors,
the
following message
is
displayed:
Memory
Failed
at
AAAAAAAA
(W:BBCCDDEE.
R:FFGGHHII)
This
error
message
can
be
decoded as shown:
W:
BBCCDDEE
is
the
write
pattern.
R:
FFGGHHII
is
the
read
pattern.
BB
and
FF
are
at
address AAAAAAAA.
CC
and
GG
are
at
address AAAAAAAA +
1.
DD
and
EE
are
at
address
AAAAAAAA+2.
EE
and
II
are
at
address
AAAAAAAA+3.
For
byte
wide memory
test
errors,
the
following message is displayed:
Memory
Failed
at
AAAAAAAA
(W:BBCCDDEE.
R:FFGGHHII)
This
error
message
can
be
decoded as:
W:
BBCCDDEE
is
the
write
pattern.
R:
FFGGHHII
is
the
read
pattern.
BB
and
FF
are
at
address AAAAAAAA.
CC
and
GG
are
at
address
AAAAAAAA+2.
DD
and
EE
are
at
address AAAAAAAA
+4.
EE
and
II are
at
address
AAAAAAAA+6.
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