SSTATUS_VS_SHIFT
#define SSTATUS_VS_DIRTY (0x3 << SSTATUS_VS_SHIFT)
#define SSTATUS_VS_MASK (0x3 << SSTATUS_VS_SHIFT)
#define SSTATUS_VS_OFF (0x0 << SSTATUS_VS_SHIFT)
#define SSTATUS_VS_INITIAL (0x1 << SSTATUS_VS_SHIFT)
#define SSTATUS_VS_CLEAN (0x2 << SSTATUS_VS_SHIFT)