Motorola DSP56301 Processing Interrupt Source Priorities Within an IPL, Priority Interrupt Source

Models: DSP56301

1 372
Download 372 pages 304 b
Page 93
Image 93

Configuring Interrupts

Table 4-6.Interrupt Sources (Continued)

Interrupt

Interrupt

 

Priority Level

Interrupt Source

Starting Address

Range

 

 

 

 

 

 

VBA:$52

0–2

SCI receive data with exception status

 

 

 

VBA:$54

0–2

SCI transmit data

 

 

 

VBA:$56

0–2

SCI idle line

 

 

 

VBA:$58

0–2

SCI timer

 

 

 

VBA:$5A

0–2

Reserved

 

 

 

VBA:$5C

0–2

Reserved

 

 

 

VBA:$5E

0–2

Reserved

 

 

 

VBA:$60

0–2

Host receive data full

 

 

 

VBA:$62

0–2

Host transmit data empty

 

 

 

VBA:$64

0–2

Host command (default)

 

 

 

VBA:$66

0–2

Reserved

 

 

 

:

:

:

 

 

 

VBA:$FE

0–2

Reserved

 

 

 

4.4.3Processing Interrupt Source Priorities Within an IPL

If more than one interrupt request is pending when an instruction executes, the interrupt source with the highest IPL is serviced first. When several interrupt requests with the same IPL are pending, another fixed-priority structure within that IPL determines which interrupt source is serviced first. Table 4-7shows this fixed-priority list of interrupt sources within an IPL, from highest to lowest at each level The interrupt mask bits in the Status Register (I[1–0]) can be programmed to ignore low priority-level interrupt requests.

 

Table 4-7.Interrupt Source Priorities Within an IPL

 

 

 

 

 

 

 

 

 

Priority

 

 

 

 

 

Interrupt Source

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Level 3 (nonmaskable)

 

 

 

 

 

 

 

Highest

 

Hardware

RESET

 

 

 

 

 

 

 

 

 

 

Stack error

 

 

 

 

 

 

 

 

 

Illegal instruction

 

 

 

 

 

 

 

 

 

Debug request interrupt

 

 

 

 

 

 

 

 

 

Trap

 

 

 

 

 

 

Lowest

 

 

Nonmaskable interrupt

 

 

 

 

 

 

 

 

 

 

 

 

 

Levels 0, 1, 2 (maskable)

 

 

 

 

 

 

Highest

 

 

IRQA

(external interrupt)

 

 

 

 

 

 

 

 

 

 

(external interrupt)

 

 

 

 

IRQB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Core Configuration

4-19

Page 93
Image 93
Motorola DSP56301 user manual Processing Interrupt Source Priorities Within an IPL, Priority Interrupt Source