Software Downloading

Software Downloading







Software is ordered via VIDA replacement parts catalogue (upgrades are ordered via VIDA software manager). This procedure describes the software manager procedure between the VIDA station and the car.

The control modules are preprogrammed by the supplier using the primary boot loader. The aim of the software is that VIDA and the factory systems should be able to load software to the car. This software contains a number of commands, the primary boot loader commands, which handle the actual download and function while there are no applications in the control module.

The primary boot loader is in the section of the control module called the Read Only Memory (ROM). The ROM cannot be erased. If the primary boost loader gets erased it would not be possible to establish contact with the control module. Therefore the ROM is important. Downloading would not be possible.

There are five cables between the data link connector (DLC) and the central electronic module. Two of these are for CAN_H and CAN_L, for the high speed section of the Control area network (CAN). Two for CAN_H and CAN_L, for the low speed section of the Controller area network (CAN).

The fifth cable is called the Communication line (C-Line). The four Control area network (CAN) cables are connected to the diagnostic relays which are normally open.

When downloading starts a command is sent via the communication link telling the central electronic module to close the diagnostic relays. Communication cannot occur between the VIDA station and the Controller area network (CAN) before this is carried out.

These relays protect the Controller area network (CAN) from short-circuiting.

VIDA then transmits a reset command to the car. The reset command is sent so that all control modules are restarted. Then VIDA transmits a command so that the control modules continue in their programming mode. This is always carried out by the primary boot loader even if the control module is loaded with the software.

Each time a control module is supplied with power the primary boot loader starts within the first 20 ms.

If the control module receives a programming command during these 20 ms, the control module continues in the programming mode.

Otherwise the control module receives application software over the function in the control module.

This means that it is always possible to put a control module into programming mode, even if the application software is corrupted.

For example, in the event of a download failure.

The programming command is transmitted for approximately 2 seconds so that all the control modules will have time to understand the command and continue in programming mode. In programming mode the control modules stop sending Controller Area Network (CAN) messages and await new software.

The secondary boot loader file is run (if applicable) after the primary boot loader. Any old software is erased so that it will not affect the new software being downloaded. Then the software is downloaded into the control module. A restart command to return from the programming mode to normal position is transmitted to the car. All control modules then continue in normal mode.