section 7 - Index of

MOVE Move Data MOVEOperation:S~DAssembler Syntax:MOVE S,DDescription: Move the contents of the specified data source S to the specified destinationD. This instruction is equivalent to a data ALU NOP with a parallel data move.When a 56-bit accumulator (A or B) is specified as a source operand S, the accumulatorvalue is optionally shifted according to the scaling mode bits SO and S 1 in the systemstatus register (SR). If the data out of the shifter indicates that the accumulator extensionregister is in use and the data is to be moved into a 24- or 48-bit destination, the valuestored in the destination D is limited to a maximum positive or negative saturation constantto minimize truncation error. Limiting does not occur if an individual 24-bit accumulatorregister (A1, AO, B1, or BO) is specified as a source operand instead of the full 56-bitaccumulator (A or B). This limiting feature allows block floating-point operations to beperformed with error detection since the L bit in the condition code register is latched.When a 56-bit accumulator (A or B) is specified as a destination operand 0, any 24-bitsource data to be moved into that accumulator is automatically extended to 56 bits bysign extending the MS bit of the source operand (bit 23) and appending the source operandwith 24 LS zeros. Similarly, any 48-bit source data to be loaded into a 56-bit accumulatoris automatically sign extended to 56 bits. Note that for 24-bit source operandsboth the automatic sign-extension and zeroing features may be disabled by specifyingthe destination register to be one of the individual 24-bit accumulator registers (A 1 orB1). Similarly, for 48-bit source operands, the automatic sign-extension feature may bedisabled by using the long memory move addressing mode and specifying A10 or B10 asthe destination operand.Example:MOVE XO,A 1;move XO to A 1 without sign ext. or zeroingxo ~I ________ ~$2_34_5_67 __ ~ xol ~ ________ ~$2_3_45_67 __ ~A I~ __ $F_F_:F_FF_FF_F_:F_FF_F_FF __ ~A ~I ____ $_FF_:2_34_56_7_:F_FF_FF_F __--I