topic Re: MC9s08JM32 clock initialisation in 8-bit Microcontrollers

MC9s08JM32 clock initialisation

stevec — Thu, 11 Jun 2009 21:02:56 GMT

I have just decided to use the JM32 device because of its 24MHz max bus speed and 12 bit A/D, having used the 9S08RE16 device before. I am having problems understanding how to achieve this maximum bus speed. When I was selecting the device I thought it was just a simple job of running off a 48MHz crystal! Can someone point me in the right direction here. I wish to use an external crystal and have all internal processes working off 24MHz. I have tried using Device Initialiser within Codewarrior but to no avail.

Steve

Re: MC9s08JM32 clock initialisation

pgo — Fri, 12 Jun 2009 09:21:43 GMT

Dear stevec,

See this thread for some example code:

http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&message.id=13898#M13898

bye

Re: MC9s08JM32 clock initialisation

stevec — Fri, 12 Jun 2009 13:47:22 GMT

Hi pgo,

Thanks for the link. Looks like it's what I need.

I'm a bit concerned about the reference to BDM speed. Something else I shall have to check out! I'm using a P&E MultiLink Interface. I've just found it works with a bus speed of up to 35MHz so I should be ok.

Steve