[NISTC_AO_MODE3_REG]            = { 0x18c, 2 },
        [NISTC_RESET_REG]               = { 0x190, 2 },
        [NISTC_INTA_ENA_REG]            = { 0x192, 2 },
-       [Second_IRQ_A_Enable_Register]  = { 0, 0 }, /* E-Series only */
+       [NISTC_INTA2_ENA_REG]           = { 0, 0 }, /* E-Series only */
        [Interrupt_B_Enable_Register]   = { 0x196, 2 },
        [Second_IRQ_B_Enable_Register]  = { 0, 0 }, /* E-Series only */
        [AI_Personal_Register]          = { 0x19a, 2 },
         * dma requests for their counters
         */
        if (gpct_index == 0) {
-               reg = Second_IRQ_A_Enable_Register;
+               reg = NISTC_INTA2_ENA_REG;
                if (enable)
-                       val = G0_Gate_Second_Irq_Enable;
+                       val = NISTC_INTA_ENA_G0_GATE;
        } else {
                reg = Second_IRQ_B_Enable_Register;
                if (enable)
 
 #define NISTC_RESET_AI                 BIT(0)
 
 #define NISTC_INTA_ENA_REG             73
+#define NISTC_INTA2_ENA_REG            74
 #define NISTC_INTA_ENA_PASSTHRU0       BIT(9)
 #define NISTC_INTA_ENA_G0_GATE         BIT(8)
 #define NISTC_INTA_ENA_AI_FIFO         BIT(7)
 #define AO_START1_Interrupt_Enable             _bit1
 #define AO_BC_TC_Interrupt_Enable              _bit0
 
-#define Second_IRQ_A_Enable_Register   74
-enum Second_IRQ_A_Enable_Bits {
-       AI_SC_TC_Second_Irq_Enable = _bit0,
-       AI_START1_Second_Irq_Enable = _bit1,
-       AI_START2_Second_Irq_Enable = _bit2,
-       AI_START_Second_Irq_Enable = _bit3,
-       AI_STOP_Second_Irq_Enable = _bit4,
-       AI_Error_Second_Irq_Enable = _bit5,
-       G0_TC_Second_Irq_Enable = _bit6,
-       AI_FIFO_Second_Irq_Enable = _bit7,
-       G0_Gate_Second_Irq_Enable = _bit8,
-       Pass_Thru_0_Second_Irq_Enable = _bit9
-};
-
 #define Second_IRQ_B_Enable_Register   76
 enum Second_IRQ_B_Enable_Bits {
        AO_BC_TC_Second_Irq_Enable = _bit0,