MPC5554 CAN Baudrate init

[A_Nagy]

Hi,

I'm using an MPC5554 on a development board from phytec. On the development board is a crystal with 8MHz, fSYS is set to 128MHz.

I init my CAN interface with 166kBaud. The clock source is the crystal, the Bus is working. My register value is : 0x02DB0006 (CANA.CR).

This means:

PRESDIV = 2

RJW=3

PSEG2=3

PSEG1=3

CLK_src=0

PROPSEG=6

When I init my CAN interface with 1MBaud. The clock source couldn't be longer the crystal.

My register value is : 0x07DB2006 (CANA.CR).

This means:

PRESDIV = 7

RJW=3

PSEG2=3

PSEG1=3

CLK_src=1

PROPSEG=6

The Bus isn't working!

Could anybody see a mistake? 

[T_Ks]

Hallo      A Nagy

I hope you see this mail I am interested in your project spezial this MPC 5554 CAN connection

can you mail me ? I now it is an year agoo maybe you read it .

tks12xvodafone.nl

Best regards T.Kienhuis

[A_Nagy]

Hi there!

I found my problem, the two definitions of the CAN Pins were wrong. The value has to be:

  SIU.PCR[83].R  = 0x060F; // FlexCAN_A_CNTX -> primary function
  SIU.PCR[84].R  = 0x050F; // FlexCAN_A_CNRX -> primary function

The value for the Config Register:

  CAN_A.CR.R = 0x0F122000

With this coniguration my CAN Interface works with 1MBaud!

//*******************************************

//  (fSYS = 128MHz, fOSC = 8MHz)

#define CAN_BAUD_1M      0x0F122000
#define CAN_BAUD_500k    0x00360000
#define CAN_BAUD_250k    0x01360000 

Message Edited by A.Nagy on 2009-09-02 10:56 AM