MPLL_BYPASSCLK_SEL
orig = data = RREG32_SMC(MPLL_BYPASSCLK_SEL);
WREG32_SMC(MPLL_BYPASSCLK_SEL, data);
orig = data = RREG32(MPLL_BYPASSCLK_SEL);
WREG32(MPLL_BYPASSCLK_SEL, data);