3.3.12.1 Data Accumulators

Two 72-bit data accumulators, ACCA and ACCB, are the Result registers for the DSP instructions listed in DSP Multiply Instructions. Each accumulator is not memory-mapped and is referred as these three registers, where ‘x’ denotes the particular accumulator:

• ACCxL: ACCx[31:0]
• ACCxH: ACCx[63:32]
• ACCxU: ACCx[71:64]

For fractional operations that use the accumulators, the radix point is located to the right of bit 31. The range of fractional values that can be stored in each accumulator is -256 to +(256 - 2**-63).

For integer operations that use the accumulators, the radix point is located to the right of bit 0. The range of integer values that can be stored in each accumulator is -0x80_00000000_00000000 to 0x7F_FFFF_FFFF_FFFF_FFFF.