National Instruments 320571-01 用户手册
Using the DMA VIs
Chapter 4
Part 4: NI-DSP Interface Utilities
4-4
NI-DSP SRM for LabVIEW for Windows
DSP DMA Copy(LV to DSP)
Copies the data in the LabVIEW array
source to the destination(DSP
Address) on the DSP board using the
onboard DMA method.
source to the destination(DSP
Address) on the DSP board using the
onboard DMA method.
This VI uses only the DMA controller
on the DSP board to transfer data.
Therefore, it does not interfere with
the other program that is running on
the DSP board unless you copy the
data to the DSP memory location that
is being used by the other program.
on the DSP board to transfer data.
Therefore, it does not interfere with
the other program that is running on
the DSP board unless you copy the
data to the DSP memory location that
is being used by the other program.
Note:
This VI does not convert floating-point data to DSP format while copying. When you copy floating data,
convert to DSP format in your program on the DSP board before using this data. However, the Copy
Mem(LV to DSP) VI automatically converts data format during the copying procedure.
convert to DSP format in your program on the DSP board before using this data. However, the Copy
Mem(LV to DSP) VI automatically converts data format during the copying procedure.
The source buffer can contain one of three kinds of data–float (32-bit), short (16-bit), and long (32-bit). To copy
different types of data, you must wire the source data buffer to the appropriate source terminal. For example, if you
want to copy floating data, you must wire the data buffer to the terminal source(float). You must wire only one
source terminal. The destination buffer must be large enough to contain all of the data from the source buffer.
different types of data, you must wire the source data buffer to the appropriate source terminal. For example, if you
want to copy floating data, you must wire the data buffer to the terminal source(float). You must wire only one
source terminal. The destination buffer must be large enough to contain all of the data from the source buffer.
slot is the board ID number. slot defaults to 3.
source(float) is the terminal to which you must wire the source buffer if the data you want to copy is
a 32-bit floating-point data array. Remember, the program on the DSP board must convert this data
to DSP format before using it.
a 32-bit floating-point data array. Remember, the program on the DSP board must convert this data
to DSP format before using it.
source(long) is the terminal to which you must wire the source buffer if the data you want to copy is
a 32-bit long data array.
a 32-bit long data array.
source(short) is the terminal to which you must wire the source buffer if the data you want to copy
is a 16-bit long data array.
is a 16-bit long data array.
destination(DSP Address) is the actual DSP address to which you want to copy your data. It should
be a 24-bit integer (such as FFF000 hex) less than or equal to FFFFFF hex. If you know the exact
DSP address where you want to store the data, you can use this address directly. Alternatively, you
can use the DSP Handle To Address VI to convert a DSP Handle Cluster to an actual DSP address.
be a 24-bit integer (such as FFF000 hex) less than or equal to FFFFFF hex. If you know the exact
DSP address where you want to store the data, you can use this address directly. Alternatively, you
can use the DSP Handle To Address VI to convert a DSP Handle Cluster to an actual DSP address.
error in(no error) contains the error information from a previous VI. If an error occurs, it is passed
out error out and no other calls are made.
out error out and no other calls are made.
error out contains the error information for this call.