Using CodeWarrior, develop and demonstrate the following assembly programs, one at a time. The program computes A-B where A and B are 8-bit unsigned binary value. The result is a four digit ASCII number, with the first ASCII digit indicating the sign and the remaining three ASCII digits the magnitude. The value of A-B is assumed to be representable as a one-byte two's complement number. In each case, the numbers (both input and output) are to be stored in RAM and they should be declared within a data section using the assembler directive ds. b or ds. w. To fill in and/or observe values at RAM locations, you should use the data sub-window of the debug window. The input values should be filled in right before running your code.
Programs:
(1) The program converts an 8-bit unsigned binary to a three-ASCII-digit number. For example, a value 0001 0010 in binary should be converted into a 3-digit number as â0â (=$30), â1â (=$31), and â8â (=$38). A value 1111 1111 in binary should be converted into a 3-digit number as â2â, â5â, and â5â. Note: instead of $30, you should use â0â (including the single quotes) directly in the assembly code.
(2) The program computes A-B, where A and B are 8-bit unsigned binary values. The result is a four-digit ASCII number, with the first ASCII digit indicating the sign and the remaining three ASCII digits the magnitude. The value of A-B is assumed to be representable as a one-byte twoâs complement number. That is, -128 <= A-B <= 127. For example, if A = 0000 1001 (= nine) and B = 0000 1000 (= eight), then the result is a four-digit number â+â, â0â, â0â, and â1â. If A = 0000 0001 (= one) and B = 1000 0000 (= one hundred and twenty-eight), then the result is a four-digit number â-â, â1â, â2â, and â7â
Note: you may use â+â or â-â (including the single quotes) directly in the assembly code.