Control Register File

2.7.6Interrupt Enable Register (IER)

The interrupt enable register (IER) enables and disables individual interrupts. The IER is shown in Figure 2−7 and described in Table 2−9.

Figure 2−7. Interrupt Enable Register (IER)

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R-0

 

 

 

 

 

 

 

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IE15

IE14

IE13

IE12

IE11

IE10

IE9

IE8

IE7

IE6

IE5

IE4

Reserved

NMIE

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W-0

 

 

 

 

 

 

R-0

R/W-0

R-1

Legend: R = Readable by the MVC instruction; W = Writeable by the MVC instruction; -n= value after reset

Table 2−9. Interrupt Enable Register (IER) Field Descriptions

Bit

Field

Value

Description

 

 

 

 

31−16

Reserved

0

Reserved. The reserved bit location is always read as 0. A value written to this

 

 

 

field has no effect.

 

 

 

 

15−4

IEn

 

Interrupt enable. An interrupt triggers interrupt processing only if the

 

 

 

corresponding bit is set to 1.

 

 

0

Interrupt is disabled.

 

 

1

Interrupt is enabled.

 

 

 

 

3−2

Reserved

0

Reserved. The reserved bit location is always read as 0. A value written to this

 

 

 

field has no effect.

 

 

 

 

1

NMIE

 

Nonmaskable interrupt enable. An interrupt triggers interrupt processing only if

 

 

 

the bit is set to 1.

 

 

 

The NMIE bit is cleared at reset. After reset, you must set the NMIE bit to

 

 

 

enable the NMI and to allow INT15−INT4 to be enabled by the GIE bit in CSR

 

 

 

and the corresponding IER bit. You cannot manually clear the NMIE bit; a write

 

 

 

of 0 has no effect. The NMIE bit is also cleared by the occurrence of an NMI.

 

 

0

All nonreset interrupts are disabled.

 

 

1

All nonreset interrupts are enabled. The NMIE bit is set only by completing a

 

 

 

B NRP instruction or by a write of 1 to the NMIE bit.

 

 

 

 

0

1

1

Reset interrupt enable. You cannot disable the reset interrupt.

 

 

 

 

SPRU733

CPU Data Paths and Control

2-17

Page 43
Image 43
Texas Instruments TMS320C67X/C67X+ DSP manual 9. Interrupt Enable Register IER Field Descriptions