REG_F2_DEV_CNTRL1
dev_cntrl1 = reg_read32(REG_F2_DEV_CNTRL1);
reg_write32(REG_F2_DEV_CNTRL1, dev_cntrl1 | F2_DEV_CNTRL1_EN_VSFX);
reg_write32(REG_F2_DEV_CNTRL1, dev_cntrl1 & ~F2_DEV_CNTRL1_EN_VSFX);