topic Re: LPC550x CAN 2.0 vs CAN-FD in LPC Microcontrollers

LPC550x CAN 2.0 vs CAN-FD

MartinHo — Tue, 17 May 2022 11:42:42 GMT

Hi,

In evaluating to use the LPC5504, the datasheet states that there is a CAN 2.0 Controller in this Chip.

But I only find descriptions for the CAN-FD controller (integrated LPC55S04). Where can I find the description for the CAN 2.0 controller?

Martin

Re: LPC550x CAN 2.0 vs CAN-FD

xiangjun_rong — Wed, 18 May 2022 02:14:12 GMT

Hi,

First of all, pls download UN11424.pdf from the link:

https://www.nxp.com.cn/docs/en/user-guide/UM11424.pdf

Refer to the Chapter 41: LPC55S0x/LPC550x Controller Area Network
Flexible Data for CAN module.

The CAN module support CAN2.0 A/B, it supports the 29 bits ID and 11 bits ID, furthermore, it supports CAN flexible data rate feature, in other words, we can set up the data phase transfer rate.

Frankly speaking, I am not very clear about your question, if you require the CAN2.0 protocol, I suppose you can search on Google to get the link to download CAN2.0 protocol.

Hope it can help you

XiangJun Rong

Re: LPC550x CAN 2.0 vs CAN-FD

MartinHo — Wed, 18 May 2022 06:18:23 GMT

Hi,

Thanks for the fast answer, I don't need an help in understanding CAN 2.0 or CAN-FD (in developing products with CAN-Bus for more then 20 years).
What I'm searching is a description of the difference between the CAN-FD controller (in the "S" devices) and the CAN2.0 Controller (in the not "S" devices).
The UM11424 describes only the CAN-FD controller (Chapter 41, CAN2.0 is mentioned only in Chapter 1.8.1)
Also I have tried to include the CAN Controller on a LPC5504 project, but the included driver is for the CAN-FD Controller.

P.s. There is an copy and past error on Chapter 41, it's referring to the LPC55S1x/LPC551x (where all MCU’s have the CAN-FD controller)

Best regards

Martin

Re: LPC550x CAN 2.0 vs CAN-FD

xiangjun_rong — Thu, 19 May 2022 09:15:33 GMT

Hi,

The CAN controller of LPC550x can be both general CAN controller and CAN-FD controller which is dependent on the CAN control register configuration.

If the FDOE is set, this is a CAN-FD controller. if the FDOE is cleared, this is a CAN controller, flexible data rate is not supported.

Hope it can help you

XiangJun Rong

Re: LPC550x CAN 2.0 vs CAN-FD

MartinHo — Thu, 19 May 2022 09:45:15 GMT

Hi,

Thanks for the information.

If I understand You right, on the LPC5502 / LPC5504 / LPC5506 I have to set the FDOE bit to 0. while on the LPC55S04 / LPC55S06 this bit can be set to 0 or 1.

What happens if FDOE is set to 1 on the LPC5502/4/6?

It seem to me that there is no real difference between the "S" and no "S" version regarding the CAN Controller, apart from NXP guaranteeing only the CAN 2.0 mode as functioning on the no "S" MCU's.

I think this should be mentioned in the User Manual and/or the data sheet.

best regards,

Martin

Re: LPC550x CAN 2.0 vs CAN-FD

xiangjun_rong — Mon, 23 May 2022 02:27:58 GMT

Hi,

I come to know your question.

Pls refer to section 7.25 in data sheet of LPC550x, both the LPC55S0x and LPC550x have CAN-FD modules.

Anyway, I will confirm with AE team.

XiangJun Rong

Re: LPC550x CAN 2.0 vs CAN-FD

xiangjun_rong — Thu, 02 Jun 2022 01:52:22 GMT

Hi,

This is AE reply:

LPC550x only support CAN2.0 since the CAN-FD feature is not available (not enabled) for this part.

XiangJun Rong