ST92P141K4D0 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST92P141K4D0

8/16-BIT MCU FOR 3-PHASE AC MOTOR CONTROL

STMicroelectronics 

ST92141 - 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.

Example 1

In the first example, (simplest case, Figure 17) the

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.

Figure 17. Simple Example of a Sequence of Interrupt Requests with:

- Concurrent mode selected and

- IEN unchanged by the interrupt routines

0

Priority Level of

Interrupt Request

1

INTERRUPT 2 HAS PRIORITY LEVEL 2

INTERRUPT 3 HAS PRIORITY LEVEL 3

INTERRUPT 4 HAS PRIORITY LEVEL 4

INTERRUPT 5 HAS PRIORITY LEVEL 5

2

3

INT 2

4

INT 3

INT 4

5

INT 5

ei CPL = 7

6

INT 5

7

MAIN

CPL is set to 7

INT 2

CPL = 7

INT 3

CPL = 7

INT 4

CPL = 7

MAIN

CPL = 7

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