Register Associated With Dsp Instructions; Accumulator (Acc) - Renesas RX100 Series User Manual

RX13T Group
2.2.3

Register Associated with DSP Instructions

2.2.3.1

Accumulator (ACC)

b63
Undefined
Value after reset:
The accumulator (ACC) is a 64-bit register used for DSP instructions. The accumulator is also used for the multiply and
multiply-and-accumulate instructions; EMUL, EMULU, FMUL, MUL, and RMPA, in which case the prior value in the
accumulator is modified by execution of the instruction.
Use the MVTACHI and MVTACLO instructions for writing to the accumulator. The MVTACHI and MVTACLO
instructions write data to the higher-order 32 bits (bits 63 to 32) and the lower-order 32 bits (bits 31 to 0), respectively.
Use the MVFACHI and MVFACMI instructions for reading data from the accumulator. The MVFACHI and MVFACMI
instructions read data from the higher-order 32 bits (bits 63 to 32) and the middle 32 bits (bits 47 to 16), respectively.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
b48 b47
Range for reading and writing by
MVTACHI and MVFACHI
Range for reading by MVFACMI
b32 b31 b16 b15
Range for writing by MVTACLO
Page 53 of 1041
2. CPU
b0