ST92F250CV2TB STMicroelectronics, ST92F250CV2TB Datasheet - Page 97

• Manufacturer Part Number: ST92F250CV2TB
• Description: IC MCU 256K FLASH 100-TQFP
• Manufacturer: STMicroelectronics
• Series: ST9r

Specifications of ST92F250CV2TB

• Core Processor: ST9
• Core Size: 8/16-Bit
• Speed: 24MHz
• Connectivity: CAN, I²C, LIN, SCI, SPI
• Peripherals: DMA, LVD, POR, PWM, WDT
• Number Of I /o: 80
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: ST92F25x
• Core: ST9
• Data Bus Width: 8 bit, 16 bit
• Data Ram Size: 8 KB
• Interface Type: CAN, I2C, SCI, SPI
• Maximum Clock Frequency: 24 MHz
• Number Of Programmable I/os: 80
• Number Of Timers: 5 x 16 bit
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ST92F150-EPB
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 16 bit x 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-2140

ARBITRATION MODES (Cont’d)
Example 2
In the second example, (more complex,
47), each interrupt service routine sets Interrupt
Enable with the ei instruction at the beginning of
the routine. Placed here, it minimizes response
time for requests with a higher priority than the one
being serviced.
The level 2 interrupt routine (with the highest prior-
ity) will be acknowledged first, then, when the ei
instruction is executed, it will be interrupted by the
level 3 interrupt routine, which itself will be inter-
rupted by the level 4 interrupt routine. When the
level 4 interrupt routine is completed, the level 3 in-
terrupt routine resumes and finally the level 2 inter-
rupt routine. This results in the three interrupt serv-
Figure 47. Complex Example of a Sequence of Interrupt Requests with:
- Concurrent mode selected
- IEN set to 1 during interrupt service routine execution
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
ei
CPL = 7
INT 2
ei
CPL = 7
INT 3
Figure
ei
ei
CPL = 7
INT 4
ice routines being executed in the opposite order
of their priority.
It is therefore recommended to avoid inserting
the ei instruction in the interrupt service rou-
tine in Concurrent mode. Use the ei instruc-
tion only in Nested mode.
WARNING: If, in Concurrent Mode, interrupts are
nested (by executing ei in an interrupt service
routine), make sure that either ENCSR is set or
CSR=ISR, otherwise the iret of the innermost in-
terrupt will make the CPU use CSR instead of ISR
before the outermost interrupt service routine is
terminated, thus making the outermost routine fail.
ST92F124/F150/F250 - INTERRUPTS
CPL = 7
INT 3
INTERRUPT 2 HAS PRIORITY LEVEL 2
INTERRUPT 3 HAS PRIORITY LEVEL 3
INTERRUPT 4 HAS PRIORITY LEVEL 4
INTERRUPT 5 HAS PRIORITY LEVEL 5
CPL = 7
INT 2
CPL = 7
INT 5
CPL = 7
MAIN
97/429
9