Embedded Target for Motorola MPC555

Data Acquisition (DAQ) List Configuration

The Embedded Target for Motorola MPC555 supports the Data Acquisition (DAQ) List feature of the CAN Calibration Protocol (CCP). DAQ lists allow efficient synchronous signal monitoring. The CCP block provided with the Embedded Target for Motorola MPC555 supports DAQ lists (see CAN Calibration Protocol for details).

ASAP2.Signal objects are used for monitoring a signal in the CCP polling mode of operation. To monitor a signal in a DAQ list, however, you must configure the signal somewhat differently. The differences are as follows:

• Instead of defining an ASAP2.Signal in the MATLAB workspace (and associated signal in the Simulink model), define a canlib.Signal object instead.
• There is no need to set the RTWInfo.StorageClass property of the canlib.Signal object. By default, the storage class is set to Custom.
• You should enter data in the other fields of the canlib.Signal object in the same way you would do for an ASAP2.Signal object.

During code generation, the Embedded Target for Motorola MPC555 automatically determines how to configure the DAQ lists in the generated code. For each distinct sample rate (of the set of canlib.Signal objects assigned by the user) one DAQ list in the model is created. The CCP DAQ List Object Descriptor Tables (ODTs) are shared equally between the created DAQ lists.

The sample rates of the canlib.Signal objects are mapped to CCP event channels in an extra file, DAQ_LIST_EVENT_MAPPINGS, that is generated in the build directory. This shows how to assign event channels to MEASUREMENT signals in a calibration package.

The event channels periodically transmit events that are used to trigger the sending of DAQ data to the host. By assigning event channels as defined in DAQ_LIST_EVENT_MAPPINGS, consistent and efficient transmission of DAQ data is achieved.

It is the responsibility of the calibration tool (see Compatibility with Calibration Packages) to assign an event channel and data to the available DAQ lists using CCP commands, and to interpret the synchronous response.

It is the responsibility of the user to make sure the calibration tool is set up correctly and that the event channels assigned to MEASUREMENT signals correspond to those defined in the file DAQ_LIST_EVENT_MAPPINGS.

ASAP2 File Generation Procedure

Summary of the Real-Time Target