NEC Electronics' CAN-Family

Description

CAN_Chip_BG CAN is the actually most often used communication protocol in the automotive market. Standardized by ISO 11898, the CAN protocol offers a lot of flexibility, speed, transmission security and implementation at low cost.

Many microcontrollers of NEC Electronics for the automotive market have built-in CAN controller interfaces. Starting off with the low-end DCAN interface, via FCAN, up to high performance AFCAN controller interfaces. All these interfaces are certified by ISO 16845 Conformance, and have proven stability by many applications.

NEC Electronics CAN Controllers

The most recent implementation of CAN controller at NEC Electronics is AFCAN. Together with its gateway-supporting variant DAFCAN, this controller offers many features, which allow easy programming and very high performance. Due to the hardware register structure, (D)AFCAN allows structured access by C-language. The internal state-machines of the CAN controller hardware are effectively reducing the load of CPU, when receiving and transmitting messages. (D)AFCAN is using the licensed BOSCH (www.can.bosch.com) Transfer Layer, which comes from the inventors of the CAN bus.

Major Features of (D)AFCAN

16, 32 or 48 message buffer per channel available, depending on device
1Mbit/s Bus Speed @ 8 MHz controller clock achievable (with 8 TQ/bit)
Software compatibility for all (D)AFCAN controller derivates of various devices
- High re-use of software, keeping the same structured access on C-Level
- HIS and AUTOSAR compatible
Interrupts for any state transition
- All warning and error states of protocol, waking up, transmit, receive
Programmable shortcut between RX and TX
- Easy self-test implementation possible
Reception Features
- Receive History List (RHL)
  - Easy tracing of incoming message sequences
- Multi Buffer Receive Block (MBRB)
  - Receive several times the same message without disturbing the CPU
- Individual Overwrite Mode for each buffer
  - Software polling or interrupt reaction support individually selectable for each buffer
Transmit Features
- Transmit History List (THL)
  - Easy tracing of outgoing message sequences
- Automatic Block Transfer Mode (ABT)
  - Allows effective transmission of larger data blocks without CPU intervention
Enhanced Diagnosis Support (DAFCAN)
- Mirroring of messages from selectable channel to a new channel
- Monitoring of messages from selectable channel

can_diagram_s
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CiA (CAN in Automation), CCT (CAN Conformance Test)

NEC Electronics is member of CiA (www.can-cia.org), and also is certified to perform CAN Conformance Tests according to ISO 16845, in co-operation with C&S (www.cs-group.de), the well-known test house for most CAN issues.

Driver support

CAN drivers are available for a wide range of NEC Electronics' devices. Our partners for driver support are:

Vector Informatik (www.vector-cantech.com/products)
Mentor Graphics (www.mentor.com)
3Soft (www.3soft.de)
CG-Smith Software Private Limited (www.cg-smith.com) , which is part of the KPIT Cummins Company (www.kpitcummins.com)