ARM Technical Support Knowledge Articles

I'm not implementing an external coprocessor. How should I tie off the interface?

Applies to: ARM920/922T, ARM926EJ-S, ARM940T, ARM946E-S, ARM966E-S, ARM9TDMI

Answer

Make sure that the coprocessor handshake signals (CHSD and CHSE, or CHSDE and CHSEX) are tied off correctly to 2'b10 (ABSENT).

Failing to do this will cause your design to behave in an unpredictable way or hang when a Coprocessor Instruction is executed (including instructions for the Control coprocessor, CP15).

All other inputs on the CP interface should be tied low.

See also:

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