Consider the following program. Determine the final values of R20 and R21, and the final values of H. C. N. and Z flags after the program is executed. Show your work. EQU AX = 0X6C EQU BX = 0x80 LDI R21, AX INC R21 LDI R20, BX DEC R20 SUB R21, R20 R20 = R21 = H= ZE N =