USER CUSTOMIZATION
M68CPU32BUG REV 1
C-11
Table C-1. CPU32Bug Customization Area (continued)
Offset
Default Value
Mnemonic
Description
Initialization Tables
$D0-16F
all $FF’s
INITTBL
Initialization Tables #1 and #2.
The Initialization Table is organized as a series of entries each of which has the
following format:
<ADDR>
<CNT/SZ>
<FILL> <DATA>
4
1
0|1
n
<--- # bytes
Where:
<ADDR>
is the destination address for the <DATA>. It is 4 bytes long and must
start on a even address (word) boundary. A value equal to the FILL_L
value ($FFFFFFFF) terminates the routine.
<CNT/SZ>
is the count/size code for the <DATA> and is encoded as "$ns" where:
n
is the upper nibble and contains the count value minus one for
number of <DATA> elements of size "s" that are to be stored in
successive addresses, starting with <ADDR>.
s
is the lower nibble and contains the size code for the <DATA>
and the storage operation itself. Valid size codes are as follows:
1 = BYTE data
2 = WORD data
4 = LONG WORD data
An invalid size code terminates the routine.
<FILL>
is a dummy placeholder/filler that is only present for WORD and
LONG WORD sized <DATA> so they will be aligned on an even
address (word) boundary. Thus the fill byte is not present for BYTE
data, otherwise it is one byte long.
<DATA>
is the byte, word, or long word data as specified by <CNT/SZ> that is
to be stored starting at <ADDR>. This field contains exactly s*(n+1)
data bytes. If the data size is BYTE (s=1) and there are an even number
of <DATA> elements (n+1 is odd), then one filler byte is added so the
next Table entry will start on an even address (word) boundary.