Read and write memory locations on an FPGA board from MATLAB
aximaster object communicates with the
MATLAB® AXI master IP when it is running on an FPGA board. The object forwards
read and write commands to the IP to access slave memory locations on the FPGA board.
Before using this object, follow the steps in Set Up for MATLAB AXI Master.
mem = aximaster(vendor) returns an object,
mem, that controls an AXI4 master IP for the FPGA
vendor that is running on your board. This connection enables
you to access memory locations in an SoC design from MATLAB.
mem = aximaster(vendor,Name,Value, ...) returns an object,
mem, with additional properties specified by one or more
Name,Value pair arguments.
vendor— FPGA brand name
Specify the manufacturer of your FPGA board. The AXI master IP varies depending on the type of FPGA you have.
JTAGCableName— Name of JTAG cable used for communication with FPGA board
'auto'(default) | character vector
Specify this property if more than one JTAG cable of the same type are connected to the host computer. If the host computer has more than one JTAG cable and you do not specify this property, the object returns an error. The error message contains the names of the available JTAG cables. See Select from Multiple JTAG Cables.
Interface— Type of interface used for communication with FPGA board
Specify the interface type for communicating between the host and the FPGA.
DeviceAddress— Internet protocol (IP) address of FPGA board
192.168.0.2(default) | IP address
Specify the IP address of the Ethernet port on the FPGA board.
To enable this property, set Interface to
Port— User datagram protocol (UDP) port number of FPGA board
50101(default) | unsigned 16-bit integer
Specify the UDP port value of the target FPGA as an unsigned 16-bit integer.
To enable this property, set Interface to
TckFrequency— JTAG clock frequency
Specify the JTAG clock frequency, in MHz. For Intel® FPGAs the JTAG clock frequency is 12 or 24 MHz. For Xilinx® FPGAs, the JTAG clock frequency is 33 or 66 MHz. The JTAG frequency depends on the type of cable and the maximum clock frequency supported by the FPGA board.
|readmemory||Read data out of AXI4 memory-mapped slaves|
|release||Release JTAG cable resource|
|writememory||Write data to AXI4 memory-mapped slaves|
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.
If two cables of the same type are connected to your host computer, specify the
JTAGCableName identifier for the board where the JTAG master
IP is running. To see the JTAG cable identifiers, attempt to create an
aximaster object. The object returns a list of the
current JTAG cable
h = aximaster('Xilinx')
Error using fpgadebug_mex Found more than one JTAG cable: 0 (JtagSmt1): #tpt_0001#ptc_0002#210203991642 1 (Arty): #tpt_0001#ptc_0002#210319789795 Please disconnect the extra cable, or specify the cable name as an input argument. See documentation of FPGA Data Capture or MATLAB as AXI master to learn how to set the cable name.
h = aximaster('Xilinx','JTAGCableName','#tpt_0001#ptc_0002#210319789795')