ARM Technical Support Knowledge Articles

Can the ARM7TDMI-S accept asynchronous interrupts?

Applies to: ARM7TDMI-S


If the ARM7TDMI-S receives an asynchronous interrupt on nIRQ or nFIQ, will the processor crash and if so, why?


The ARM7TDMI-S cannot accept asynchronous interrupts; nFIQ and nIRQ must be synchronous inputs and they are sampled on the rising edge of CLK.

The ARM7TDMI-S uses several blocks of logic to handle interrupts. Asynchronous interrupts can cause these internal logic blocks to contain conflicting information about the state of an interrupt.

If the ARM7TDMI-S receives an asynchronous interrupt then the behavior is unpredictable and the processor might 'crash', due to a deadlock occurring, cache corruption, etc.

Rate this article

Disagree? Move your mouse over the bar and click

Did you find this article helpful? Yes No

How can we improve this article?

Link to this article
Copyright © 2011 ARM Limited. All rights reserved. External (Open), Non-Confidential