How does HCS12 manage multiple sources of interrupts?
✓ Interrupt Priority: When there are multiple sources, several interrupts might be pending at the same time. The CPU is required to prioritize all interrupt sources. An interrupt with higher priority always receives service before interrupts with lower priorities. The HCS12 prioritize interrupts in hardware.
What is interrupt address register?
An interrupt control register, or ICR, is a hardware register in a computer chip used to configure the chip to generate interrupts—to raise a signal on an interrupt line—in response to some event occurring within the chip or a circuit connected to the chip.
What are global interrupts?
The Global Interrupt Enable bit, GIE (INTCON<7>), enables (if set) all un-masked interrupts or disables (if cleared) all interrupts. Individual interrupts can be disabled through their correspond- ing enable bits in the INTCON register. The GIE bit is cleared on reset.
What is interrupt vector address?
Interrupt vectors are addresses that inform the interrupt handler as to where to find the ISR (interrupt service routine, also called interrupt service procedure). All interrupts are assigned a number from 0 to 255, with each of these interrupts being associated with a specific interrupt vector.
What are the different types of interrupts?
Interrupts have two types: Hardware interrupt and Software interrupt. The hardware interrupt occurrs by the interrupt request signal from peripheral circuits. On the other hand, the software interrupt occurrs by executing a dedicated instruction.
What is interrupt flag register?
The Interrupt flag (IF) is a flag bit in the CPU’s FLAGS register, which determines whether or not the (CPU) will respond immediately to maskable hardware interrupts. If the flag is set to 1 maskable interrupts are enabled.
What is Intcon register?
The INTCON register is a readable and writable register, which contains various enable and flag bits for the TMR0 register overflow, RB port change and external RB0/INT pin interrupt. GIE: Global Interrupt Enable bit. 1-Enables all unmasked interrupts. 0-Disables all interrupts. PIE: Peripheral Interrupt Enable bit.
What is Gie in microcontroller?
GIE – Global Interrupt Enable 1 – Enables all unmasked interrupts. 0 – Disables all interrupts.
Which interrupt has highest priority?
TRAP
TRAP is the internal interrupt that has the highest priority among all interrupts except the divide by zero exception.
What is CLI and STI?
In a system using x86 architecture, the instructions CLI (Clear Interrupt) and STI (Set Interrupt). The POPF (Pop Flags) removes a word from the stack into the FLAGS register, which may result in the Interrupt flag being set or cleared based on the bit in the FLAGS register from the top of the stack.