TMS320F28377D: TMS320F28377D

Ashrumochan NathSharma

Part Number: TMS320F28377D

Dear Friends,

I am using CAN in TMS320F28377D.I have referred the C2000 example files for can external transmit check.In that defualt Bit Time Calculation is given with API's.

But while finding i technical reference manual ,I want to calculate the BRP value using the examples given 20.12.2.2 (page no- 2009) & 20.12.2.3(page no - 2010).

I didn't understand the values how he got using the equation:

{Example -1 20.12.2.2 (page no- 2009)} = (1-1)base 3 & (8-1) base 4 &(1-1)base 2 & (1-1) base6 = 0x0000700;

{Example -2 20.12.2.3(page no- 2010)} = (4-1)base 3 & (5-1) base 4 &(4-1)base 2 & (1-1) base6 = 0x00034C1;

Can anyone please explain me this?

Regards,

Ashrumochan.

over 7 years ago

0 Hareesh Janakiraman over 7 years ago

TI__Guru* 95315 points

It appears you are using an obsolete version of the TRM. Please use the latest version at: http://www.ti.com/lit/ug/spruhm8g/spruhm8g.pdf

The formula for bit-rate is: CAN module clock/ [BRP x Bit-time]

BRP is the value of BRPreg + 1. Bit-time = (TSEG1reg + 1) + (TSEG2reg + 1) + 1

In the above equations BRPreg , TESG1reg and TSEG2reg represent the actual values written in the corresponding fields in the CANBTC register. The parameters TSEG1reg, TSEG2reg, SJWreg, and BRPreg are automatically enhanced by 1 when the CAN module accesses these parameters.

Example 1:

BRP is 1. Bit-time is 10.

Example 2:

BRP is 2. Bit-time is 10.

I agree all this is not clear in the TRM. We are working on an update and have already marked this up for clarification.

You may also want to refer to this helpful resource: http://www.ti.com/lit/an/sprac35/sprac35.pdf

0 Ashrumochan NathSharma over 7 years ago in reply to Hareesh Janakiraman

Intellectual 400 points

Thanks Hareesh,

I will look through this.

Regards,

Ashrumochan

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TMS320F28377D: TMS320F28377D