Texas Instruments TMS320 User Manual page 102

Real-Time Data Exchange
3.8.3.1 Target to Host Data Flow
3.8.3.2 Host to Target Data Flow
3.8.3.3 RTDX Target Library User Interface
3-40
To record data on the target, you must declare an output channel and write
data to it using routines defined in the user interface. This data is immediately
recorded into an RTDX target buffer defined in the RTDX target library. The
data in the buffer is then sent to the host via the JTAG interface.
The RTDX host library receives this data from the JTAG interface and records
it. The host records the data into either a memory buffer or to an RTDX log
file (depending on the RTDX host recording mode specified).
The data can be retrieved by any host application that is an OLE automation
client. Some typical examples of OLE-capable host applications are:
❏ Visual Basic applications
❏ Visual C++ applications
❏ Lab View
❏ Microsoft Excel
Typically, an RTDX OLE automation client is a display that allows you to
visualize the data in a meaningful way.
For the target to receive data from the host, you must first declare an input
channel and request data from it using routines defined in the user interface.
The request for data is recorded into the RTDX target buffer and sent to the
host via the JTAG interface.
An OLE automation client can send data to the target using the OLE
Interface. All data to be sent to the target is written to a memory buffer within
the RTDX host library. When the RTDX host library receives a read request
from the target application, the data in the host buffer is sent to the target via
the JTAG interface. The data is written to the requested location on the target
in real time. The host notifies the RTDX target library when the operation is
complete.
The user interface provides the safest method of exchanging data between a
target application and the RTDX host library.
The data types and functions defined in the user interface handle the
following functions:
❏ Enable a target application to send data to the RTDX host library
❏ Enable a target application to request data from the RTDX host library