ARM Technical Support Knowledge Articles


Applies to: MCBSTR9 Evaluation Board


Information in this article applies to:


Using the Keil BLINKY example for the MCBSTR9 board, everything runs OK at 24MHz, but when I change the PLL post-divider value (PLL_PDIV) from 3 to 2 in the STARTUP.S file to run at 96MHz, then download and run, the program does not run (no LEDs blink). What's wrong?


When you set the PLL post-divider value (PLL_PDIV) to 2, you must change the Clock Control Register (SCU_CLKCNTR) to the following:


This applies to earlier silicon revisions of STR91x which had a problem with System reset at 96MHz and it was not possible to use a 96MHz clock for FMI (see page 12). This was fixed in STR91x Rev D with date code 618 and later and in STR91xFA.


Article last edited on: 2008-04-16 03:09:24

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