The HCS12 / 9S12: An Introduction to Software and Hardware Interfacing (Book) (2nd Edition) Question;

You are going to write a subroutine CRN Convert to Roman Numeral. You will use the unimplemented opcode trap to do this. CRN = $18FF. The instruction in assembler will look like CRN 16bit-address or CRN add_16 where add_16 is the location of a 16 bit signed integer; the number to be converted to Roman Numerals. If the argument is invalid, set add_16 to -1. If [add_16]>0 and <5000, valid; else invalid. If valid, it is the Roman Numeral equivalent such as the string MCMV. So CRN foo, where foo contains 2017, would reset foo to the string MMXVII0. If foo contained 0, it would be reset to -1 (ie FFFE). Use $FFF8 as the trap location for the Unimplemented OpCode trap location. 1. Make a flow chart of the code 2. Implement it in assembler 3. In point form, state how you would configure memory before executing a program FRED which uses CRN.