A-1 Instruction Description Notation - Motorola DSP56000 Manual

Xn Input Register X1 or X0 (24 Bits)
Yn Input Register Y1 or Y0 (24 Bits)
An Accumulator Registers A2, A1, A0 (A2 — 8 Bits, A1 and A0 — 24 Bits)
Bn Accumulator Registers B2, B1, B0 (B2 — 8 Bits, B1 and B0 — 24 Bits)
X Input Register X = X1: X0 (48 Bits)
Y Input Register Y = Y1: Y0 (48 Bits)
A Accumulator A = A2: A1: A0 (56 Bits)*
B Accumulator B = B2: B1: B0 (56 BIts)*
AB Accumulators A and B = A1: B1 (48 Bits)*
BA Accumulators B and A = B1: A1 (48 Bits)*
A10 Accumulator A = A1: A0 (48 Bits)
B10 Accumulator B= B1:B0 (48 bits)
* NOTE: In data move operations, shifting and limiting are performed when this register is specified
as a source operand. When specified as a destination operand, sign extension and possibly
zeroing are performed.
Rn Address Registers R0 - R7 (16 Bits)
Nn Address Offset Registers N0 - N7 (16 Bits)
Mn Address Modifier Registers M0 - M7 (16 Bits)
MOTOROLA
NOTATION
Table A-1 Instruction Description Notation
Data ALU Registers Operands
Address ALU Registers Operands
INSTRUCTION SET DETAILS A - 5