Explain what it is that is used with a 9S12 processor to mat

Explain what it is that is used with a 9S12 processor to match a given interrupt request with its corresponding ISR.

Solution

  Each ISR have the some vector location in the memory. The interrupts are generated by the hardware or software. The software interrupts are generated by programming, hardware interrupts are generated by external triggerring pulses. When the interrupt request came by software or hardware the PC (Program Counter) automatically loaded the vector address of the matched Interrupt request ISR. The vector address have 8bytes of memory only in that 4 bytes for base address and 4 bytes for offset of the ISR.

The on-chip resources of the 9s12 (freescale) MCU are controlled and enhanced by numerous interrupts. These ISR-controlled resources include:

A 16-channel 10-bit A/D converter,

Pulse-Width Modulated (PWM) outputs on PortP,

Enhanced Capture/Timer (ECT) I/O on PortT,

A watchdog timer (COP),

A clock monitor,

Maskable and nonmaskable external interrupt pins,

Real-Time Interrupt (RTI),

Dual serial communications ports,

A high speed serial peripheral interface (SPI)

An inter-IC (IIC) serial bus, and,