Programmer-generated error message.
FAIL [{ string | expression}[ ,...]]
The FAIL directive causes the Assembler to output an error message. The total error count is incremented as with any other error. The FAIL directive is normally used in conjunction with conditional assembly directives for exceptional condition checking. The assembly proceeds normally after the error has been printed. An arbitrary number of strings and expressions, in any order but separated by commas with no intervening white space, can be optionally specified to describe the nature of the generated error.
A label is not allowed with this directive.
FAIL 'Parameter out of range'