Block Of Memory Search (Bs) - Motorola M68CPU32BUG User Manual

BS
3.6 BLOCK OF MEMORY SEARCH
BS <range><del><text> [;B|W|L] or
BS <range><del><data>[<del><mask>] [;B|W|L|N|V]
The BS command searches the specified range of memory for a match with a user-entered data
pattern. This command has three modes:
Mode 1 LITERAL STRING SEARCH — executes a search for the ASCII equivalent of
the literal string entered by the user. Mode 1 is indicated if <RANGE> is followed
by a <text> field. The size as specified in the option field defines whether the
count field in <range> refers to bytes, words, or longwords. The option field is
available only if <range> is specified using a count. If a match is found then the
address of the first byte of the match is output.
Mode 2 DATA SEARCH — a data pattern is entered by the user as part of the command
line. The data field size is entered by the user in the option field; the default is
word (W). The size entered in the option field also dictates whether the count field
in <RANGE> refers to bytes, words, or longwords. The following occurs during a
data search:
1. The user-entered data pattern is right-justified. Leading bits are truncated
2. Successive bytes, words, or longwords, within the specified range, are
3. If the ''N'' (non-aligned) option has been selected then the data is searched
4. If a match is found, the address of the first byte of the match is output
Mode 3 DATA VERIFICATION — If the ''V'' (verify) option is selected and the memory
contents do not match the user-specified pattern, then addresses and data are
displayed. Otherwise this mode is identical to Mode 2.
M68CPU32BUG/D REV 1
Block of Memory Search
or leading zeros are added as necessary to make the data pattern the
specified size.
compared to the user-entered data. Comparison is made only on those bits
at bit positions corresponding to a 1 in the mask. If no mask is specified
then a default mask of all one's is used (all bits are compared). The size of
the mask is the same size as the data.
on a byte-by-byte basis, rather than by words or longwords regardless of
the size of <data>. This is useful if a word (or longword) pattern is being
sought, but is not expected to lie on a word (or longword) boundary.
along with the memory contents. If a mask was in use, then the actual data
at the memory location is displayed, rather than the masked data.
3-10
DEBUG MONITOR COMMANDS
BS