ST92E163-EPB/US STMicroelectronics, ST92E163-EPB/US Datasheet - Page 50

• Manufacturer Part Number: ST92E163-EPB/US
• Description: KIT DEMO MASS STORAGE
• Manufacturer: STMicroelectronics
• Type: Microcontroller Programmerr

Specifications of ST92E163-EPB/US

• Contents: Programmer, Cable, Power Supply, Software, Manual and more
• For Use With/related Products: ST9 MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ST92163R4 - INTERRUPTS
ARBITRATION MODES (Cont’d)
Examples
In the following two examples, three interrupt re-
quests with different priority levels (2, 3 & 4) occur
simultaneously during the interrupt 5 service rou-
tine.
Figure 22. Simple Example of a Sequence of Interrupt Requests with:
- Concurrent mode selected and
- IEN unchanged by the interrupt routines
50/230
0
1
2
3
4
5
6
7
CPL is set to 7
Priority Level of
Interrupt Request
MAIN
INT 5
ei
CPL = 7
INT 5
INT 2
INT 3
INT 4
CPL = 7
INT 2
CPL = 7
INT 3
CPL = 7
Example 1
In the first example, (simplest case,
ei instruction is not used within the interrupt serv-
ice routines. This means that no new interrupt can
be serviced in the middle of the current one. The
interrupt routines will thus be serviced one after
another, in the order of their priority, until the main
program eventually resumes.
INT 4
CPL = 7
MAIN
INTERRUPT 2 HAS PRIORITY LEVEL 2
INTERRUPT 3 HAS PRIORITY LEVEL 3
INTERRUPT 4 HAS PRIORITY LEVEL 4
INTERRUPT 5 HAS PRIORITY LEVEL 5
Figure
22) the