MaskWidth=12
OverWrite=yes
HelloWorld 11110000xxxx
MaskWidth=12
OverWrite=yes
Nine 1001xxxxxxxxxxxx
Eight 1000xxxxxxxxxxxx
Seven 0111xxxxxxxxxxxx
Six 0110xxxxxxxxxxxx
MaskWidth=12
OverWrite=yes
GENERIC 1111xxxxxxxx
OPCODE1 111100100000
| << Contents << Other Topics << Symbol Tables |
| BitMask Symbol Table Files |
| A bit-mask file is a special type of text symbol table. Symbol names are associated with bit-masks. The bit-masks matches multiple values to each symbol name. |
| Formatting rules |
| * To create a bit-mask file, use the following header lines at the start of the text file... |
| Bitmasks |
| If "Bitmasks=yes", then each symbolic value is a bit-mask instead of a plain value. |
| MaskWidth |
| "MaskWidth=(number)" defines the total bits in each bit-mask. |
| Overwrite |
| If "Overwrite=yes", then duplicate values overwrite the prior symbol strings. If Overwrite=no or is missing, the duplicate values are ignored. |
| * Use a ";" character (semi-colon) at the line start to comment-out the line. |
| * At least one space or tab character must separate each symbol name and the bit-mask. |
| * The bit-masks must use "0", "1", and "x" characters. The "x" character means that the associated bit matches both 0 and 1 values. No spaces can appear in the bit-mask. |
| * The number of bits in each mask must match the "MaskWidth=X" header line. |
| * The lines can use bitmask-first or symbol-first order. |
| * The first line in the file determines the format. Value-first lines cannot be mixed with symbol-first lines. |
| * All lines use the same order. Value-first order cannot be mixed with symbol-first order. |
| * No extra text is allowed in the file. |
| * The file size is unlimited. |
| An optional Color Attribute can be added to each line. |
| Examples |
|
BitMasks=yes MaskWidth=12 OverWrite=yes HelloWorld 11110000xxxx |
| The symbol name "HelloWorld" matches all values 0xF00 to 0xF0F. |
| Here is an example using a 16-bit bit-mask... |
|
BitMasks=yes MaskWidth=12 OverWrite=yes Nine 1001xxxxxxxxxxxx Eight 1000xxxxxxxxxxxx Seven 0111xxxxxxxxxxxx Six 0110xxxxxxxxxxxx |
| In both examples above, there are no conflicts between bit-masks. Here is an example of using the "OverWrite=yes" header line..... |
|
BitMasks=yes MaskWidth=12 OverWrite=yes GENERIC 1111xxxxxxxx OPCODE1 111100100000 |
| The "GENERIC" symbol covers all values 0xF00 to 0xFFF. The "OPCODE1" line overwrites the symbol for 0xF20 because it occurs later in the file and the "OverWrite=yes" header line was used. |
| Copyright and trademark information |
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