section 7 - Index of

JLC (R2+N2)will requireand will execute in= (1 +ea)= (1 +0)= 1= (4+jx)instruction program word= (4+ea+(2 * ap»= (4+ea+(2 * wp»= (4+2+(2 * 4» oscillator clock cycles.= 14Example 18: RTll!lstructionproblem: Calculate the number of 24-bit instruction program words and the number ofoscillator clock cycles required for the instructionRTIwhereOperating Mode Register (OMR)Sus Control Register (SCR)Return Address (on the stack)= 02 (normal expanded memory map),= $0012, and,= $0100 (internal P memory).Solution: To determine the number of instruction program words and the number ofoscillator clock cycles required for the given instruction, the user should perform the followingoperations:1. Look up the number of instruction program words and the number of oscillator clockcycles required for the opcode-operand portion of the instruction in Table A-6.According to Table A-6, the RTI instruction will require one instruction program word andwill execute in (4+rx) oscillator clock cycles. The term "rx" represents the number of additional(if any) oscillator clock cycles required for an RTI or RTS instruction.2. Evaluate the "rx" term using Table A-12.According to Table A-12, the RTI instruction will require rx=(2 * ap) additional oscillator-clock cycles. The term "ap" represents the number of additional (if any) oscillator clockcycles that are required to access a P memory operand. Note that the term "(2 * ap)" representsthe two program memory instruction fetches executed at the end of an RTI orRTS instruction to refill the instruction pipeline.