Microchip Technology Inc.: New flash microcontrollers switch between CAN and FIFO mode

The Control Area Network (CAN) product lineup of Microchip Technology Inc. has recently expanded with a new generation of 48 KB and 64 KB flash memory microcontroller.

By Control Engineering Staff September 8, 2003
Microchip’s new 8-bit PICmicro MCUs target complex embedded command-and-control networks in automotive and general-purpose markets. They’re available now in 64- and 80-lead TQFP and 68-lead PLCC packages.

The Control Area Network (CAN) product lineup of Microchip Technology Inc . has recently expanded with a new generation of 48 KB and 64 KB flash memory microcontrollers (PIC18F8680/6680 and PIC18F8585/6585) that integrate a new, flexible CAN 2.0B interface. Called ECAN module, the interface features configurable transmit and receive (TX/RX) buffers, offering either standard CAN operation or FIFO (first in, first out) data mode.

Benefits of ECAN module include ability to configure multiple applications on a single node; easier implementation to a software-protocol bridge from a CAN network, and allowing the microcontroller (MCU) to be reused for different applications. ECAN module’s three software-configurable operating modes support multiple functions (including DeviceNet):

  • Mode 0 (Legacy) permits reuse of application code previously developed for Microchip’s existing PIC18CX58 or PIC18FXX8 CAN interface MCUs.

  • Mode 1(Enhanced) supplies added resources and wider functionality, including three dedicated TX buffers, two dedicated RX buffers, and six independently configurable TX/RX buffers. Also featured are 16 acceptance filters, two filter masks, and an automatic remote transmission request response.

  • Mode 2 (FIFO) provides RX buffers set up in a FIFO configuration (not directly associated with a given acceptance filter). CAN bus messages are stored in the eight FIFO buffers based on the sequence in which they are received.

Demonstration boards—PICDEM CAN LIN 1 and 2—are available for $199 each to show the CAN module’s functionality on PIC18CX58 and PIC18FXX8 devices. The kits include preprogrammed firmware on a sample device, PC software, and documentation for simulating a CAN network.

—Frank J. Bartos, executive editor, fbartos@reedbusiness.com