AN2432 Freescale Semiconductor / Motorola, AN2432 Datasheet - Page 2

• Manufacturer Part Number: AN2432
• Description: LIN Sample Application for the MC68HC908EY16 Evaluation Board
• Manufacturer: Freescale Semiconductor / Motorola

AN2432/D
Use of the evaluation board without additional hardware
2
LIN Sample Application for the MC68HC908EY16 Evaluation Board
The software for this LIN monitor is listed in appendix I. It is simplified by the
use of software drivers (reference [2]) that deal with the serial LIN protocol.
These drivers use the MC68HC908EY16’s SCI module to interface with the LIN
physical interface (MC33399) and allow the application code to use simple
Application Program Interface (API) function calls to read status information
and data from the LIN messages. This application note, as well as describing
the LED LIN monitor, outlines how the drivers can be used to develop other LIN
applications.
The evaluation board is supplied with the LEDemo application programmed
into FLASH memory. It will function as described in this application note by
simply applying 8-12 volts to the battery (B1) or LIN (P2) connector. This
assumes that three jumpers are fitted: J2, J1 (IRQ-IRQ HIGH) and P4 (pin11-
pin13).
The main use of the board is, however, to facilitate the development of LIN
applications and for this a programming and development environment needs
to be added. The most sophisticated high level language programming and
development environment is Metrowerks Codewarrior. A limited version of
Codewarrior is available on the WEB (www.metrowerks.com) and also on the
CD supplied with the evaluation board. This version is limited to 1K of code but
a free 4K license upgrade is available from [e-mail].
Downloading and installation may require full “admin” access to the PC. Accept
the suggested paths and defaults (e.g. do not select FlexLM option). For
FLASH programming and assembly code development P&E’s PROG08SZ and
ICS software is suitable. These are available free from www.pemicro.com.
There are 3 main ways of connecting the evaluation board to the development
environment.
The simplest in hardware terms is to use the board in monitor mode using an
RS232 connection to a PC “COM” port. All that is required is an 8-12 volt supply
(at B1 or P2) and a 9-pin straight-through “D” cable to a PC running appropriate
software. Use of the P&E tools is very straightforward. In order to get into
monitor mode at 9600 baud all that is required is the installation of the
9.8304MHz canned oscillator module and the addition of a link between pins 2
(IRQ) and 3 (VTST) of J1. This provides 9 volts to the IRQ pin. No other links
should be installed. The board supplies pull-ups and pull-downs to provide the
appropriate levels on pins A1, B3 and B4 for entry into monitor mode.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA