Datasheet

User manual Rev. 12.3 — 10 June 2014 320 of 547

17.1 How to read this chapter

The C_CAN block is available in LPC11Cxx parts only (LPC11C00 series).

17.2 Features

The on-chip drivers are stored in boot ROM and offer CAN and CANopen initialization and

communication features to user applications via a defined API. The following functions are

included in the API:

• CAN set-up and initialization

• CAN send and receive messages

• CAN status

• CANopen Object Dictionary

• CANopen SDO expedited communication

• CANopen SDO segmented communication primitives

• CANopen SDO fall-back handler

17.3 General description

In addition to the CAN ISP, the boot ROM provides a CAN and CANopen API to simplify

CAN application development. It covers initialization, configuration, basic CAN

send/receive as well as a CANopen SDO interface. Callback functions are available to

process receive events.

17.3.1 Differences to fully-compliant CANopen

While the bootloader uses the SDO communication protocol and the Object Dictionary

data organization method, it is not a fully CiA 301 standard compliant CANopen node. In

particular, the following features are not available or different to the standard:

• No Network Management (NMT) message processing.

• No Heartbeat Message, no entry 0x1017.

• Uses proprietary SDO Abort Codes to indicate device errors

• “Empty” SDO responses during SDO segmented download/write to the node are

shortened to one data byte, rather than full eight data bytes as the standard

describes. This to speed up the communication.

• Entry [1018h,1] Vendor ID reads 0x0000 0000 rather than an official CiA-assigned

unique Vendor ID. This in particular because the chip will be incorporated into designs

of customers who will become the “vendor” of the whole device. The host will have to

use a different method to identify the CAN ISP devices.

• The maximum OD entries allowed is 255.

UM10398

Chapter 17: LPC11Cxx C_CAN on-chip drivers

Rev. 12.3 — 10 June 2014 User manual