Release JTAG cable resource
release(mem) releases the JTAG cable resource,
freeing the cable for use to reprogram the FPGA. After initialization,
the AXI master object,
mem, holds the JTAG cable
resource, and other programs cannot access the JTAG cable. While you
have an active AXI master object, FPGA programming over JTAG fails.
release method before reprogramming
To use this object, you must have a design running on an FPGA board connected to the MATLAB® host machine. The FPGA design must include an AXI master IP customized for your FPGA vendor. This IP is included with the support package installation. For how to include the IP in your project, see Access FPGA External Memory Using MATLAB as AXI Master.
Create a MATLAB AXI master object. The object connects with the FPGA board and confirms that the IP is present.
mem = aximaster('Altera')
mem = aximaster with properties: Vendor: 'Altera' JTAGCableName: 'auto'
Write and read one or more addresses with one command. By default, the commands auto-increment the address for each word of data. For instance, write ten addresses. Then read from a single location.
writememory(mem,140,[10:19]) rd_d = readmemory(mem,140,1)
rd_d = uint32 10
Or, read from ten locations.
rd_d = readmemory(mem,140,10)
rd_d = 1×10 uint32 row vector 10 11 12 13 14 15 16 17 18 19
BurstType property to
'Fixed' to turn off
the auto-increment and access the same address multiple times. For instance, read ten times from
the same address.
rd_d = readmemory(mem,140,10,'BurstType','Fixed')
rd_d = 1×10 uint32 row vector 10 10 10 10 10 10 10 10 10 10
Write ten times to the same address. Note that the final value stored in address
writememory(mem,140,[20:29],'BurstType','Fixed') rd_d = readmemory(mem,140,10)
rd_d = 1×10 uint32 row vector 29 11 12 13 14 15 16 17 18 19
Alternatively, specify the address as a hexadecimal string. To cast the read data to a data
type other than
uint32, use the
writememory(mem,'1c',[0:4:64]) rd_d = readmemory(mem,'1c',16,'OutputDataType',numerictype(0,6,4))
rd_d = Columns 1 through 10 0 0.2500 0.5000 0.7500 1.0000 1.2500 1.5000 1.7500 2.0000 2.2500 Columns 11 through 16 2.5000 2.7500 3.0000 3.2500 3.5000 3.7500 DataTypeMode: Fixed-point: binary point scaling Signedness: Unsigned WordLength: 6 FractionLength: 4
When you no longer need to access the board, release the JTAG connection.