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LSL Logical ~hlft Left LSLOperation:47 24c..-I ....... ------ 1..- 0 (parallel move)Assembler Syntax: LSL D (parallel move)Description: Logically shift bits 47-24 <strong>of</strong> the destination operand D one bit to the leftand store the result in the destination accumulator. Prior to instruction execution, bit 47 <strong>of</strong>D is shifted into the carry bit C, and a zero is shifted into bit 24 <strong>of</strong> the destination accumulatorD. This instruction is a 24-bit operation. The remaining bits <strong>of</strong> the destination operandD are not affected. If a zero shift count is specified, the carry bit is cleared. Thedifference between LSL and ASL is that LSL operates on only A1 or B1 and always,clears the V bit.Example:LSL B1 #$7F,RO;shift B1 one bit to the left, set up ROB ~I __Before Execution$_0_0:F_O_1~_4_:1_35_7_9B __ ~SRI,-__________ $0_3_00 __----'B ~I ___After Execution$_OO_:E_02_4_~_:1_35_79_B __ ~SRI~ __________ $0_3_09 __ ~Explanation <strong>of</strong> Example: Prior to execution, the 56-bit B accumulator contains thevalue $OO:F01234:13579B. The execution <strong>of</strong> the LSL B instruction shifts the 24-bit valuein the B1 register one bit to the left and stores the result back in the B1 register.

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