topic Re: how MCF52232/MCF52236 replace MCF52233/52235? in ColdFire/68K Microcontrollers and Processors

how MCF52232/MCF52236 replace MCF52233/52235?

gxd — Mon, 13 Oct 2008 14:24:11 GMT

I used MCF52233 and mcf52235 CPU for 2 years before.

MCF52233 system clock is 60MHz but new product is 50MHz.

For new product MCF52232/MCF52236 ,how to revise old source code in this change?

(the source code is based on AN3455 ).

void
mcf5223_pll_init(void)
{
/* The PLL pre-divider affects this!!! no change!
* Multiply 25Mhz reference crystal /CCHR by 12 to acheive system clock of 60Mhz
*/

MCF_CLOCK_SYNCR = MCF_CLOCK_SYNCR_MFD(4) | MCF_CLOCK_SYNCR_CLKSRC| MCF_CLOCK_SYNCR_PLLMODE | MCF_CLOCK_SYNCR_PLLEN ;

while (!(MCF_CLOCK_SYNSR & MCF_CLOCK_SYNSR_LOCK))
{
}
}

ADD:

MCF_CLOCK_CCHR=0x05; //// 25MHz*12/6=50MHz

Whether need I do more thing except there?

Message Edited by gxd on 2008-10-13 08:25 AM

Re: how MCF52232/MCF52236 replace MCF52233/52235?

gxd — Mon, 13 Oct 2008 14:36:07 GMT

I try it but the ethernet not pass.

i redefine SYSTEM_CLOCK 50 (mcf52235evb.h)

I find the problem in there:

void mcf5223_ePHY_init(void)
{
uint32   myctr;      //generic counter variable
uint16   mymrdata, mymwdata;    //temp variable for MII read/write data
uint16  reg0, reg1, reg4;    //

fec_mii_init((SYSTEM_CLOCK));

......

}

Need more ?

Re: how MCF52232/MCF52236 replace MCF52233/52235?

mjbcswitzerland — Tue, 14 Oct 2008 16:07:52 GMT

Hi

MCF_CLOCK_CCHR can not be changed - see the errata (this may however be corrected in newer chips).

For 60MHz operation MCF_CLOCK_SYNCR is set to 0x4007 ((25MHz / 5) * 12).
For 50MHz operation MCF_CLOCK_SYNCR is set to 0x3007 ((25MHz / 5) * 10).

Regards

Mark

www.uTasker.com

Message Edited by mjbcswitzerland on 2008-10-14 11:08 AM

Re: how MCF52232/MCF52236 replace MCF52233/52235?

MrBean — Thu, 16 Oct 2008 17:17:25 GMT

mjbcswitzerland wrote:

MCF_CLOCK_CCHR can not be changed - see the errata (this may however be corrected in newer chips).

In newer chips it indeed can be changed, very limited though.

See:

http://forums.freescale.com/freescale/board/message?board.id=CFCOMM&message.id=2316&jump=true