ARM Technical Support Knowledge Articles

During our simulation we see a hold time violation on nIRQ relative to BCLK. Is it worth synchronizing nIRQ (and nFIQ) to BCLK externally? What happens when the ARM720T is running off FCLK?

Applies to: ARM720T

Answer

The warnings from the model simply indicate that the interrupt was too close to the clock edge to have been recognised on that particular clock cycle. Inside the ARM720T, the ARM7TDMI ISYNC signal is tied off to indicate asynchronous inputs, so interrupts will also be synchronized internally (and always have a 1 cycle penalty for synchronization).

Article last edited on: 2008-09-09 15:47:37

Rate this article

[Bad]
|
|
[Good]
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