[U-Boot-Users] MPC5840 local bus speed

[Gerrit Van de Velde]

Hi all,

I'm not sure if it's entirely on topic but here we go:
We've been trying to set the local bus speed of the MPC8540 to 82MHz
without much success until now. We're using Uboot 1.1.4 with our own
board.c code mostly ripped from the 8540ADS board.
In the code there's some info about a workaround for the DLL of te cpu:

 /*
         * Errata LBC11.
         * Fix Local Bus clock glitch when DLL is enabled.
         *
         * If localbus freq is < 66Mhz, DLL bypass mode must be used.
         * If localbus freq is > 133Mhz, DLL can be safely enabled.
         * Between 66 and 133, the DLL is enabled with an override
workaround.
         */

But actually, the 82Mhz is in between those values. In this code, the
U-Boot stops working after the LCRR is assigned and doesn't even get to
the udelay part (checked with printfs)

lbc->lcrr = CFG_LBC_LCRR & (~0x80000000); /* DLL Enabled */
Udelay(200);

Disabling or enabling has the same result, the clock speed of the bus
has changed though to 82MHz (checked it with the scope).

Has anyone of you some pointers on what to check or what to try out?

Regards,
Gerrit