Processing Interrupt Source Priorities Within An Ipl; Interrupt Source Priorities Within An Ipl - Motorola DSP56303 User Manual

Configuring Interrupts
Interrupt
Priority Level
Starting Address
VBA:$50
VBA:$52
VBA:$54
VBA:$56
VBA:$58
VBA:$5A
VBA:$5C
VBA:$5E
VBA:$60
VBA:$62
VBA:$64
VBA:$66
:
VBA:$FE
4.4.3

Processing 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 4-6 shows 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.
Priority
Highest
Lowest
4-22
Table 4-5. Interrupt Sources (Continued)
Interrupt
Range
0–2 SCI receive data
0–2 SCI receive data with exception status
0–2 SCI transmit data
0–2 SCI idle line
0–2 SCI timer
0–2 Reserved
0–2 Reserved
0–2 Reserved
0–2 Host receive data full
0–2 Host transmit data empty
0–2 Host command (default)
0–2 Reserved
: :
0–2 Reserved
Table 4-6. Interrupt Source Priorities Within an IPL
Level 3 (nonmaskable)
Hardware RESET
Stack error
Illegal instruction
Debug request interrupt
Trap
Nonmaskable interrupt
DSP56303 User's Manual
Interrupt Source
Interrupt Source