Supported Data Types
Converting HDL Data to Send to MATLAB or Simulink
If your HDL application needs to send HDL data to a MATLAB^{®} function or a Simulink^{®} block, you may first need to convert the data to a type supported by MATLAB and the HDL Verifier™ software.
To program a MATLAB function or a Simulink block for an HDL model, you must understand the type conversions required by your application. You may also need to handle differences between the array indexing conventions used by the HDL you are using and MATLAB (see following section).
The data types of arguments passed in to the function determine the following:
The types of conversions required before data is manipulated
The types of conversions required to return data to the HDL simulator
The following table summarizes how the HDL Verifier software converts supported VHDL^{®} data types to MATLAB types based on whether the type is scalar or array.
VHDLtoMATLAB Data Type Conversions
VHDL Types...  As Scalar Converts to...  As Array Converts to... 

STD_LOGIC , STD_ULOGIC ,
and BIT  A character that matches the character literal for the desired logic state.  
STD_LOGIC_VECTOR , STD_ULOGIC_VECTOR , BIT_VECTOR , SIGNED ,
and UNSIGNED  A column vector of characters (as defined in VHDL Conversions for the HDL Simulator) with one bit per character.  
Arrays of STD_LOGIC_VECTOR , STD_ULOGIC_VECTOR , BIT_VECTOR , SIGNED ,
and UNSIGNED  An array of characters (as defined above) with a size that is equivalent to the VHDL port size.  
INTEGER and NATURAL  Type int32 .  Arrays of type int32 with a size that is
equivalent to the VHDL port size. 
REAL  Type double .  Arrays of type double with a size that is
equivalent to the VHDL port size. 
TIME  Type double for time values in seconds and
type int64 for values representing simulator time
increments (see the description of the 'time' option
in hdldaemon ).  Arrays of type double or int64 with
a size that is equivalent to the VHDL port size. 
Enumerated types  Character vector or string scalar that contains the MATLAB representation of a VHDL label or character literal. For example, the label
high converts to 'high'
and the character literal 'c' converts to
'''c''' .  Cell array of character vectors or string array with each element equal to a label for the
defined enumerated type. Each element is the MATLAB representation of a VHDL label or character literal. For example, the vector
(one, '2', three) converts to the column
vector ['one'; '''2'''; 'three'] . A userdefined
enumerated type that contains only character literals, and then
converts to a vector or array of characters as indicated for the
types STD_LOGIC_VECTOR ,
STD_ULOGIC_VECTOR ,
BIT_VECTOR , SIGNED , and
UNSIGNED . 
The following table summarizes how the HDL Verifier software converts supported Verilog^{®} data types to MATLAB types. The software supports packed arrays up to 128bits for Verilog.
VerilogtoMATLAB Data Type Conversions
Verilog Types...  Converts to... 

wire , reg  A character or a column vector of characters that matches the character literal for the desired logic states (bits). 
The following table summarizes how the HDL Verifier software converts supported SystemVerilog data types to MATLAB types. The software supports packed arrays up to 128bits for SystemVerilog.
SystemVerilogtoMATLAB Data Type Conversions
SystemVerilog Types...  Converts to... 

wire , reg ,
logic  A character or a column vector of characters that matches the character literal for the desired logic states (bits). 
integer
 A 32element column vector of characters that matches the character literal for the desired logic states (bits). Supported for outputs only. 
bit  boolean /ufix1 
byte  int8/uint8 
shortint  int16/uint16 
int  int32 
longint  int64/uint64 
real  double 
packed array 

^{a} For currently supported packed array input or output to the HDL Cosimulation block, the total number of bits in the packed array has a 128 upper limit. 
Note
SystemVerilog support includes signals of the above types. The following SystemVerilog types are not supported:
Unpacked arrays and multidimensional arrays
shortreal
SystemVerilog typeSystemVerilog aggregate types such as
struct
andunion
SystemVerilog interfaces
BitVector Indexing Differences Between MATLAB and HDL
In HDL, you have the flexibility to define a bitvector with either MSB0 or LSB0 numbering. In MATLAB, bitvectors are always considered LSB0 numbering. In order to prevent data corruption, it is recommended that you use LSB0 indexing for your HDL interfaces.
If you define a logic vector in VHDL as:
signal s1 : std_logic_vector(7 downto 0);
Or in Verilog as:
reg[7:0] s1;
It is mapped to int8 in MATLAB, with s1[7] as the MSB. Alternatively, if you define your VHDL logic vector as:
signal s1 : std_logic_vector(0 to 7);
Or in Verilog as:
reg[0:7] s1;
It is mapped to int8 in MATLAB, with s1[0] as the MSB.
Array Indexing Differences Between MATLAB and HDL
In multidimensional arrays, the same underlying OS memory buffer
maps to different elements in MATLAB and the HDL simulator (this
mapping only reflects different ways the different languages offer
for naming the elements of the same array). When you use both the matlabtb
and matlabcp
functions,
be careful to assign and interpret values consistently in both applications.
In HDL, a multidimensional array declared as:
type matrix_2x3x4 is array (0 to 1, 4 downto 2) of std_logic_vector(8 downto 5);
has a memory layout as follows:
bit 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24  dim1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 dim2 4 4 4 4 3 3 3 3 2 2 2 2 4 4 4 4 3 3 3 3 2 2 2 2 dim3 8 7 6 5 8 7 6 5 8 7 6 5 8 7 6 5 8 7 6 5 8 7 6 5
This same layout corresponds to the following MATLAB 4x3x2 matrix:
bit 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24  dim1 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 dim2 1 1 1 1 2 2 2 2 3 3 3 3 1 1 1 1 2 2 2 2 3 3 3 3 dim3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Therefore, if H is the HDL array and M is the MATLAB matrix, the following indexed values are the same:
b1 H(0,4,8) = M(1,1,1) b2 H(0,4,7) = M(2,1,1) b3 H(0,4,6) = M(3,1,1) b4 H(0,4,5) = M(4,1,1) b5 H(0,3,8) = M(1,2,1) b6 H(0,3,7) = M(2,2,1) ... b19 H(1,3,6) = M(3,2,2) b20 H(1,3,5) = M(4,2,2) b21 H(1,2,8) = M(1,3,2) b22 H(1,2,7) = M(2,3,2) b23 H(1,2,6) = M(3,3,2) b24 H(1,2,5) = M(4,3,2)
You can extend this indexing to Ndimensions. In general, the dimensions—if numbered from left to right—are reversed. The rightmost dimension in HDL corresponds to the leftmost dimension in MATLAB.
Converting Data for Manipulation
Depending on how your simulation MATLAB function uses the data it receives from the HDL simulator, you may need to code the function to convert data to a different type before manipulating it. The following table lists circumstances under which you would require such conversions.
Required Data Conversions
If You Need the Function to...  Then... 

Compute numeric data that is received as a type other than double 
Use the datas(inc+1) = double(idata); 
Convert a standard logic or bit vector to an unsigned integer or positive decimal 
Use the uval = mvl2dec(oport.val) This example assumes the standard logic or bit vector is
composed of the character literals The See 
Convert a standard logic or bit vector to a negative decimal 
Use the following application of the
suval = mvl2dec(oport.val, true); This example assumes the standard logic or bit vector is
composed of the character literals 
Examples
The following code excerpt illustrates data type conversion of data passed in to a callback:
InDelayLine(1) = InputScale * mvl2dec(iport.osc_in',true);
This example tests port values of VHDL type STD_LOGIC
and STD_LOGIC_VECTOR
by
using the all
function as follows:
all(oport.val == '1'  oport.val == '0')
This example returns True
if all elements
are '1'
or '0'
.
Converting Data for Return to the HDL Simulator
If your simulation MATLAB function needs to return data to the HDL simulator, you may first need to convert the data to a type supported by the HDL Verifier software. The following tables list circumstances under which such conversions are required for VHDL and Verilog.
Note
When data values are returned to the HDL simulator, the char array size must match the HDL type, including leading zeroes, if applicable. For example:
oport.signal = dec2mvl(2)
will only work if signal
is a 2bit type
in HDL. If the HDL type is anything else, you must specify
the second argument:
oport.signal = dec2mvl(2, N)
where N is the number of bits in the HDL data type.
VHDL Conversions for the HDL Simulator
To Return Data to an IN Port of Type...  Then... 

STD_LOGIC , STD_ULOGIC ,
or BIT 
Declare the data as a character that matches the character
literal for the desired logic state. For
iport.s1 = 'X'; %STD_LOGIC iport.bit = '1'; %BIT 
STD_LOGIC_VECTOR , STD_ULOGIC_VECTOR , BIT_VECTOR , SIGNED ,
or UNSIGNED 
Declare the data as a column vector or row vector of characters (as defined above) with one bit per character. For example: iport.s1v = 'X10ZZ'; %STD_LOGIC_VECTOR iport.bitv = '10100'; %BIT_VECTOR iport.uns = dec2mvl(10,8); %UNSIGNED, 8 bits 
Array of STD_LOGIC_VECTOR , STD_ULOGIC_VECTOR , BIT_VECTOR , SIGNED ,
or UNSIGNED  Declare the data as an array of type character with a size that is equivalent to the VHDL port size. See Array Indexing Differences Between MATLAB and HDL. 
INTEGER or NATURAL  Declare the data as an array of type iport.int = int32(1:10)'; 
REAL 
Declare the data as an array of type iport.dbl = ones(2,2); 
TIME  Declare a VHDL
iport.t1 = int64(1:10)'; %Simulator time %increments iport.t2 = 1e9; %1 nsec 
Enumerated types  Declare the data as a character vector or string scalar for scalar ports or a cell
array of character vectors or string array for array ports with
each element equal to a label for the defined enumerated type.
The iport.char = {'''A''', '''B'''}; %Character %literal iport.udef = 'mylabel'; %Userdefined label 
Character array for standard logic or bit representation 
Use the oport.slva =dec2mvl([23 99],8)'; 
Verilog Conversions for the HDL Simulator
To Return Data to an input Port
of Type...  Then... 

reg , wire 
Declare the data as a character or a column vector of characters that matches the character literal for the desired logic state. For example: iport.bit = '1'; 
SystemVerilog Conversions for the HDL Simulator
To Return Data to an input Port
of Type...  Then... 

reg , wire ,
logic 
Declare the data as a character or a column vector of characters that matches the character literal for the desired logic state. For example: iport.bit = '1'; 
integer  Declare the data as a 32element column vector of characters (as defined above) with one bit per character. 
Packed arrays are supported up to 128bits.
Note
SystemVerilog support includes only scalar signals of the above types. The following SystemVerilog types are not supported:
Arrays and multidimensional arrays
shortreal
SystemVerilog typeSystemVerilog aggregate types such as
struct
andunion
SystemVerilog interfaces
Simulink Handling of Wide HDL Ports
When your HDL module has a port that is wider than 128 bits, Simulink creates a vector of ports to represent this port. The Cosimulation Wizard infers the size of the HDL port. You can then set the Simulink Word Length parameter in the HDL Cosimulation block.
For input ports — Simulink port dimensions are determined at compile time by the data type of the driving signal. For example:
When HDL Word Length = 150 and Simulink Word Length = 50, HDL Verifier allows a Simulink port with data width of 50 bits, and dimensions of size 3 such as
sfix50(3)
orufix50(3)
.When HDL Word Length = 140 and Simulink Word Length = 50, HDL Verifier packs 150 bits of Simulink into 140 bits of HDL. HDL Verifier ignores the 10 most significant bits (MSB) of the last word.
For output ports
HDL Verifier creates a vector of ports to represent the output port. For example:
When HDL Word Length = 150 and Simulink Word Length = 50, HDL Verifier creates a Simulink port with data width of 50 bit. For example
sfix50(3)
orufix50(3)
.When HDL Word Length = 150 and Simulink Word Length = 60, HDL Verifier creates a Simulink port with data width of 60, such as
sfix60(3)
orufix60(3)
. Since the HDL word has only 150 bits, and the Simulink port requires 180 bits, 30 bits are padded or sign extended.When HDL Word Length = 140 and Simulink Word Length = 50, every 50 bits of the HDL output are represented as a Simulink word. The 10 MSB of the last Simulink word are unused and extended according to the Sign parameter.
See Also
Cosimulation Wizard  HDL Cosimulation  hdlverifier.HDLCosimulation