ST92F150CV1 STMicroelectronics, ST92F150CV1 Datasheet - Page 96

• Manufacturer Part Number: ST92F150CV1
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST92F150CV1

• Internal Memory: Single Voltage FLASH up to 256 Kbytes, RAM up to 8Kbytes, 1K byte E3 (Emulated EEPROM)
• Minimum Instruction Time: 83 ns (24 MHz int. clock)

ST92F124/F150/F250 - 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 46. Simple Example of a Sequence of Interrupt Requests with:
- Concurrent mode selected and
- IEN unchanged by the interrupt routines
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9
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
46) the