RX62N Group, RX621 Group
(9) Accumulator (ACC)
2. CPU
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.
R01DS0052EJ0110 Rev.1.10
Feb 10, 2011
Page 49 of 146
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