/* mask/unmask an interrupt */
#define mask(intr) do {REG_IE &= ~(1 << (intr));} while(0)
#define unmask(intr) do {REG_IE |= 1 << (intr);} while(0)
/* mask/unmask an interrupt */
#define mask(intr) do {REG_IE &= ~(1 << (intr));} while(0)
#define unmask(intr) do {REG_IE |= 1 << (intr);} while(0)