AM335X DCAN module

xing lui

Intellectual 990 points

hi,

I want to debug the DCAN module of AM335X. The CAN_CLK is 24MHz,and the CAN bit rate is 250 KBit/s.

The bit time parameters is configured as follows:

  TSeg1 = 0x4
  TSeg2 = 0x3
  Tsjw = 0x1
  BRP = 12

so the BTR register is programmed to 0x0000230B.

is that right?

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Check section 23.4.1.4 of the AM335X TRM Rev. J. If the actual timing parameters you need are those you posted all values programmed in BTR should be -1, so 0x0000230B seems correct.

0 xing lui over 11 years ago in reply to Biser Gatchev-XID

Intellectual 990 points

hi,biser,

However,the interrupt can't be generated when other CAN module send data frame to it. the interrupt is enabled.

the CTL register is 0x0000140A

0 Biser Gatchev-XID over 11 years ago in reply to xing lui

TI__Guru**** 393215 points

What software are you using?

0 xing lui over 11 years ago in reply to Biser Gatchev-XID

Intellectual 990 points

The software is written by myself,and I refer to the AM335X DCAN Linux Driver(drivers/net/can/d_can/d_can.c)

0 Biser Gatchev-XID over 11 years ago in reply to xing lui

TI__Guru**** 393215 points

For bare metal programming I would recommend that you base your code on the Starterware package. It can be freely downloaded from http://software-dl.ti.com/dsps/dsps_public_sw/am_bu/starterware/latest/index_FDS.html. The user guide can be found here: http://processors.wiki.ti.com/index.php/StarterWare_02.00.01.01_User_Guide. There is also a dedicated forum for Starterware: http://e2e.ti.com/support/embedded/starterware/default.aspx

0 xing lui over 11 years ago in reply to Biser Gatchev-XID

Intellectual 990 points

The DCAN example code in the Starterware package is without IF3 interface. I want to know whether the IF3 can automatically be updated with received message objects without DMA.

23.4.1.45 IF3OBS Register (offset = 140h) [reset = 0h]

If an interrupt line is available for IF3, an interrupt will be generated by IF3Upd flag.See the device-specific data sheet for the availability of this interrupt source.With this interrupt, the observation status bits and the IF3Upd bit could be used by the application to realize the notification about new IF3 content in polling or interrupt mode.

How to configure this interrupt？This interrupt is EDMA interrupt(CAN_IF3DMA event)?

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AM335X DCAN module