HD6417750RF240DV Datasheet, PDF (338/1132 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family / SH7750 Series

Section 9 Power-Down Modes
SH7750, SH7750S, SH7750R Group
9.9 Usage Notes
9.9.1 Note on Current Consumption
After a power-on reset, the current consumption may exceed the maximum value for sleep mode
or standby mode during the period until one or more of the arithmetic operation or floating-point
operation instructions listed below is executed.
1. Arithmetic operation instructions
MAC.W, MAC.L
2. Floating-point operation instructions
⎯ When FPSCR.PR = 0
FADD, FSUB, FMUL, FMAC, FLOAT, FTRC, FDIV, FSQRT, FIPR, FTRV
⎯ When FPSCR.PR = 1
FADD, FSUB, FMUL, FLOAT, FTRC, FDIV, FSQRT, FCNVSD, FCNVDS
Workaround: After a power-on reset, execute one or more of the above instructions before
transitioning to sleep mode or standby mode.
Example: To reduce the effect on FPSCR, arrange the following two instructions starting at
H'A0000000.
Address
H'A0000000
H'A0000002
:
Instruction String
FLDI1 FR0
FADD FR0, FR0 ; FLDI1 FR0 loads 1 into FR0,
:
; so the cause and flag bits of FPSCR are not set to 1.
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R01UH0456EJ0702 Rev. 7.02
Sep 24, 2013