FPGA Central

I have inherited a design with a component written in VHDL. This
component has some ports which are constrained integers, and one port is
a user defined type. This component is instantiated in verilog module.
When I try and run the verilog module, ModelSim (ver 6.1f) complains as
follows:

# ** Fatal: (vsim-3362) The type of VHDL port 'regfilecontrol' is
invalid for Verilog connection (15th connection).

Here is the offending VHDL port definition
regFileControl : out tRegFile(sizeOfRegFile+startOfRegFile-1
downto startOfRegFile);

Here's the corresponding actual port parameter in the verilog code where
the offending component is instantiated.

reg [(kMemMapSize*8)-1:0] ctrlReg;


These ports on the VHDL components also generated the same error.

readDelay : in integer range 0 to 7; -- specifies how
long to wait before returning data
secondaryDelay : in integer range 0 to 7; -- specifies
how long to wait before reading data from the secondary PLD

I fixed the above problem by changing the port type to
std_logic_vector(2 downto 0)

It appears to me that ModelSim will only allow a limited subset of
possible VHDL port types to be mapped to an upper level verilog module -
namely, std_logic or std_logic vector

Any suggestion on how I can circumvent this without massively changing
the existing VHDL code, which is not an option. The VHDL module in
question is actually a configuration interface to a proprietary bus
interface. I am replacing it with some stub code with literal register
values specified in my code, as that is sufficient for the functionality
I am developing. My goal was to replace their fully functional module
with my stub module, while maintaining the same port interface
structure. Complicating this is the presence of a package file which
contains the port prototypes for many of the modules - not just the
problem module.

Any ideas or comments from this verilog noob?

TIA - Urb


keeping all of tehI am actually replacing the customer's VHDL module

Paul Urbanus wrote:

> It appears to me that ModelSim will only allow a limited subset of
> possible VHDL port types to be mapped to an upper level verilog module -
> namely, std_logic or std_logic vector

True.

> Any suggestion on how I can circumvent this without massively changing
> the existing VHDL code, which is not an option.

I would write a vhdl wrapper entity that
instances the untouchable vhdl module
and converts the problem ports to std_logic_vector
and just passes the other ports through.

> Complicating this is the presence of a package file which
> contains the port prototypes for many of the modules - not just the
> problem module.

The package is only needed to compile the component
and the wrapper. The verilog part won't use it.

> Any ideas or comments

The wrapper will have to be modified if the
interface configuration is changed.
Good luck.

-- Mike Treseler

"Paul Urbanus" <[email protected]> wrote in message
news:[email protected] t...
>I have inherited a design with a component written in VHDL. This component
>has some ports which are constrained integers, and one port is a user
>defined type. This component is instantiated in verilog module. When I try
>and run the verilog module, ModelSim (ver 6.1f) complains as follows:
>
> # ** Fatal: (vsim-3362) The type of VHDL port 'regfilecontrol' is invalid
> for Verilog connection (15th connection).
>
> Here is the offending VHDL port definition
> regFileControl : out tRegFile(sizeOfRegFile+startOfRegFile-1 downto
> startOfRegFile);
>
> Here's the corresponding actual port parameter in the verilog code where
> the offending component is instantiated.
>
> reg [(kMemMapSize*8)-1:0] ctrlReg;
>
>
> These ports on the VHDL components also generated the same error.
>
> readDelay : in integer range 0 to 7; -- specifies how long
> to wait before returning data
> secondaryDelay : in integer range 0 to 7; -- specifies how
> long to wait before reading data from the secondary PLD
>
> I fixed the above problem by changing the port type to std_logic_vector(2
> downto 0)
>
> It appears to me that ModelSim will only allow a limited subset of
> possible VHDL port types to be mapped to an upper level verilog module -
> namely, std_logic or std_logic vector

You are out of luck wrt the user defined types (unless you are using
SystemVerilog?) but the constrained integer should be supported in a later
version.

From the 6.4c manual:

VHDL Instantiation Criteria Within Verilog
You can instantiate a VHDL design unit within Verilog or SystemVerilog if it
meets the following criteria:
.. The design unit is an entity/architecture pair or a configuration.
.. The entity ports are of type: bit, bit_vector, enum, integer, natural,
positive, real,
shortreal; std_logic, std_ulogic, std_logic_vector, std_ulogic_vector,
vl_ulogic,
vl_ulogic_vector, or their subtypes; unconstrained arrays; nested records;
and records
with fields of type integer, real, enum, and multi-dimensional arrays.
The port clause may have any mix of these types. Multi-dimensional arrays of
these
support types are also supported.
.. The generics are of type bit, bit_vector, integer, real, std_logic,
std_logic_vector,
vl_logic, vl_logic_vector, time, physical, enumeration, or string.
String is the only composite type allowed.

If you are using SystemVerilog you *may* be able to also resolve the custom
type by importing the VHDL package and compiling your vhdl code with
the -mixedsvvh option.

Hans
www.ht-lab.com


>
> Any suggestion on how I can circumvent this without massively changing the
> existing VHDL code, which is not an option. The VHDL module in question is
> actually a configuration interface to a proprietary bus interface. I am
> replacing it with some stub code with literal register values specified in
> my code, as that is sufficient for the functionality I am developing. My
> goal was to replace their fully functional module with my stub module,
> while maintaining the same port interface structure. Complicating this is
> the presence of a package file which contains the port prototypes for many
> of the modules - not just the problem module.
>
> Any ideas or comments from this verilog noob?
>
> TIA - Urb
>
>
> keeping all of tehI am actually replacing the customer's VHDL module