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5 interrupt clear register (icr) – Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 42

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Control Register File

CPU Data Paths and Control

2-16

SPRU733

2.7.5 Interrupt Clear Register (ICR)

The interrupt clear register (ICR) allows you to manually clear the maskable
interrupts (INT15−INT4) in the interrupt flag register (IFR). Writing a 1 to any
of the bits in ICR causes the corresponding interrupt flag (IFn) to be cleared
in IFR. Writing a 0 to any bit in ICR has no effect. Incoming interrupts have
priority and override any write to ICR. You cannot set any bit in ICR to affect
NMI or reset. The ISR is shown in Figure 2−6 and described in Table 2−8.

Note:
Any write to ICR (by the MVC instruction) effectively has one delay slot

because the results cannot be read (by the MVC instruction) in IFR until two

cycles after the write to ICR.
Any write to ICR is ignored by a simultaneous write to the same bit in the

interrupt set register (ISR).

Figure 2−6. Interrupt Clear Register (ICR)

31

16

Reserved

R-0

15

14

13

12

11

10

9

8

7

6

5

4

3

0

IC15 IC14 IC13 IC12 IC11 IC10

IC9

IC8

IC7

IC6

IC5

IC4

Reserved

W-0

R-0

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

Table 2−8. Interrupt Clear Register (ICR) 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

ICn

Interrupt clear.

0

Corresponding interrupt flag (IFn) in IFR is not cleared.

1

Corresponding interrupt flag (IFn) in IFR is cleared.

3−0

Reserved

0

Reserved. The reserved bit location is always read as 0. A value written to this
field has no effect.