0
What is an interrupt mask and when and why do you need masking?
Wiki User
∙ 10y ago
masking of interrupts is the temporal disabling of the current code the processor is executing to let higher priority ISRs (interrupt Services Routine) to be executed.
Wiki User
∙ 10y ago
Add your answer:
Earn +20 pts
What is mask-masking?
Masking is Softwear
Why do you need 8085 maskable interrupts if they can be disabled?
if u want to execute high priority interrupt,at that time of low priority running.So, we can mask the low priority interrupt and execute the high priority interrupt.
What is rim in microprocessor 8085?
RIM is Read Interrupt Mask. It is used to access the interrupt mask register, which contains the status of the three interrupt masks and the serial input data pin.
What is an maskable intErrupt?
interrupts in 8085 are basically classified into two types: 1.Maskable 2.Non maskable maskable interrupts are those which can be delayed.This is done by masking off the interrupts which are not required. Maskable interrupts are:RST 7.5,RST 6.5,RST 5.5 and INTR <decreasing order of priority>
How do you disable Interrupt request lines?
The interrupt request lines on the 8085 (INTR, RST7.5, RST6.5, and RST5.5) can be disabled using the DI (Disable Interrupt) instruction. You re-enable with the EI instruction. Also, RST7.5, RST6.5, and RST5.5 can be individually enabled and disabled using the SIM (Set Interrupt Mask) and RIM (Read Interrupt Mask) instructions. The TRAP interrupt request line cannot be disabled.
Different beetwen sim and rim?
SIM stands for “Set Interrupt Mask” It is 1 byte instruction RIM stands for “Read Interrupt Mask” it is 1 byte MULTI-PURPOSE instruction.
What happens when processor is attending an interrupt if it gets another interrupt?
The response to another interrupt request during servicing of an interrupt depends on the setting of the interrupt enable flag and/or the interrupt mask. If the interrupt service routine is thread safe, it will process correctly. More probably, problems will arise so the proper procedure is to either set the interrupt mask (8085) to not allow this or lower priority interrupts before reenabling interrupt, or to leave interrupts disabled until this iteration is complete. If interrupts are disabled or masked, a subsequent interrupt will be posted but not processed until the first is completed.
What is the meaning of maskable hardware interrupt?
A maskable hardware interrupt is one that can be disabled, or masked, by instructions in the CPU. In the 8085, all interupts except TRAP and (software) RST N can be masked by disabling interrupts, and RST7.5, RST6.5, and RST5.5 can be individually masked with the SIM (Set Interrupt Mask) instruction. In general, you leave interrupts disabled until one instruction before returning. In the case of the RST*.5 interrupts, you can mask it during interrupt processing and then enable interrupts, allowing other levels to interrupt you again. At the conclusion of the interrupt routine, you would disable interrupts, restore the mask, enable interrupts, and return. If you use this method, you can choose the nesting priority as desired. You determine what mask to set using the RIM (Read Interrupt Mask) instruction and then do bit manipulation before using SIM.
Masking Tape?
form_title= Masking Tape form_header= Purchase masking tape for your work needs. What color masking tape do you need?*= _ [50] How many rolls do you need?*= {10, 20, 30, 40, 50, More than 50} Do you need the masking tape to be waterproof?*= () Yes () No
Why there is a need for disabling interrupts in 8085?
Interrupt are automatically disabled on interrupt entry (except for TRAP, which is non-maskable) so that interrupts do not, by default, nest. You would also disable enterrupts surrounding a critical section of code that, perhaps, manipulated an interrupt register. It is possible to re-enable interrupts during an interrupt service routine. Typically, you would have a hierarchy, such as RST7.5, then RST 6.5, then RST 5.5. Initially, at interrupt entry, all interrupts are disabled. You could then manipulate the interrupt mask using the RIM and SIM instructions and enable further interrupts, allowing a nested architecture. At interrupt exit, then, you would disable interrupts, reset the mask, enable interrupts, and return from interrupt.
How do you mask xanax on a urine drug screen?
do not take xanax Also you can use "masking" solution.
Should any device be allowed to interrupt CPU while another interrupts are being serviced?
It is possible to allow nested interrupts. This is often done when there is a heirarchy of interrupts, some with higher priority than others. In order for this to work, the second interrupt must not be allowed to influence the progress of the first interrupt. We call this being "thread safe". In a nested scheme, an interrupt mask is set so that higher priority interrupts can be permitted, while blocking interrupts of the same or lower priority, and then interrupts are reenabled during the interrupt service routine. At the conclusion of the first routine, interrupts are disabled again, the mask is restored, and the normal interrupt return sequence is executed. In the 8085, this can be supported using the Read Interrupt Mask (RIM) and Set Interrupt Mask (SIM) instructions. While not strictly required, the logical priority is often INTR, RST5.5, RST6.6, RST7.5, and then TRAP, in order of increasing priority.
