OTJE PASS, CROSS ASSEMBLER FOR MICFOPROCESSORS
Mehul Patel · 1981
Paralleling the proliferation of new 8- and 16-bit m icroprocessors b eing i ntroduced on the market are an equal or l arger number of cross assemblers for these microprocessors. A problem exists in that each m icroprocessor normally requires its own cross assembler which is expen- sive and inefficient for an o rganization using many types of microprocessors, and furthermore, many of these cross assemblers are non-transport- able between host machines. This paper presents a methodology and example of structuring a table driven, u niversal, one pass, cross assembler Tor microprocessors. The methodology of the cross assembler results in a universal cross assembler in that it may be used to cross assemble source programs for many 8- and 16-bit m icroprocessors. Uy using a flagging technique to solve the problem of instructions with forward referenced a ddresses, the methodology results in a simpler one pass cross assembler as opposed to the s tandard two pass type. Finally, the methodology results in a cross assembler which is easily written in a high level language, therefore, making it trarisport- able, and it may be used efficiently in an inter- active time-shared environment, a feature which makes it attractive for use as a software develop- ment tool. 'The methodology is verified by writing and obtaining experimental results from such a cross assembler written in the BASIC-PLUS program- ming language which will execute on a IIEC PDP 11/40 minicomputer system using t he RSTS/E operat- ing system.