MPC8540 Local bus timing

[Des]

We are using the Local Bus Controller on the MPC8540 in GPCM mode. The Local Bus clock (LCLK) is set to be either 25MHz or 33MHz depending on which PCI clock frequency is used. As there is an errata (LBC11) that states that the LCLK DLL can lose lock we were recommended to select DLL bypass when LCLK is less than 66MHz. With the LCLK DLL enabled the timing of the Local Bus clock is per Figure 13.22 (Basic LBC Bus Cycle) in the Reference Manual. When the LCLK DLL is bypassed the LCLK is 180 degrees different from Figure 13.22. This leads me to ask the following questions:

1/

Is the LCLK behaviour that we observe what you would expect?

2/

Are we correct to bypass the LCLK DLL?

3/

If we bypass the LCLK DLL will that always give LCLK with exactly a 180 degree phase shift relative to Figure 13.22?

4/

If we change processor to the MPC8548E and bypass the LCLK DLL, will the MPC8548E LCLK behave exactly the same as the MPC8540?

[Des]

Further to my query, with the LCLK DLL bypassed I have changed the local bus interface on a CPLD on our board so that it is timed from an inverted version of the LCLK. I thought that that would bring the bus timing back to the way it was with the LCLK DLL enabled, but instead I needed to add an extra local bus cycle. I am now confused as to what the bus timing actually is when the LCLK DLL is bypassed. As it is not clear from the Reference Manual, please will you send me full details of the local bus timing with respect to LCLK when the LCLK DLL is bypassed.

Thanks for your help.

Derek

[joeychan]

recently ，I have a class topic about how to program eLBC on TWR_MPC8309 board.But I don't know how to start ,how to   initialize the resgisters and how to ctrol to the leds on eLBC .So can u help me?i really really really need help .Can u help me ? or send me some  simple examples  to me ?derjoeychen@gmail.com    ,thank u very much.