Release JTAG or Ethernet cable resource
release(mem) releases the JTAG cable or Ethernet cable
When using a JTAG interface, the function releases the JTAG cable resource,
freeing the cable for use to reprogram the FPGA. After initialization, the AXI
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. Call the
function before reprogramming the FPGA.
When using an Ethernet interface, the function closes the Ethernet
communications channel and clears the associated resources. During the creation
of AXI master object
mem, the object initializes a
communication stream to enable the exchange of data between the host computer
and the target processor. Call the
release function when
you no longer need to access the board.
Before you can 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 that is customized for your FPGA vendor. This IP is included with the support package installation. 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('Xilinx')
mem = aximaster with properties: Vendor: 'Xilinx' 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 example, this code writes ten addresses and then reads from a single location.
writememory(mem,140,[10:19]) rd_d = readmemory(mem,140,1)
rd_d = uint32 10
Now, 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 example, this code reads 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. In this case, 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,0x1c,[0:4:64]) rd_d = readmemory(mem,0x1c,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.