Answers Database
Foundation XVHDL: Cannot instantiate the XBlox TRISTATE component without pullups.
Record #2509
Product Family: Software
Product Line: Metamor
Product Part: Foundation XVHDL
Product Version: 2.4.4
Problem Title:
Foundation XVHDL: Cannot instantiate the XBlox TRISTATE component without pullups.
Problem Description:
Urgency: Standard
General Description:
When instantiating an XBlox TRISTATE component within a
Foundation XVHDL design, the synthesiser will complain if you
do not pass both the ENCODING and FLOAT_VAL parameters. The
only values allowed for the FLOAT_VAL parameter are PULLUP and
PULLUP_D. This means that internal tristates must have pullups
on the outputs. However, the documentation says that this
should be an 'optional' parameter.
Solution 1:
Open the Xblox.vhd file in the C:\active\VHDL\VHDL\Vhdl_lib
directory and change the following line :
component TRISTATE is
generic (FLOAT_VAL : string;
ENCODING : string := "");
to
component TRISTATE is
generic (FLOAT_VAL : string :="";
ENCODING : string := "");
by inserting the extra :=""
This will allow you to omit the FLOAT_VAL parameter in your
vhdl source code. The result will be internal tristates with
no pullups.
End of Record #2509 - Last Modified: 01/03/00 11:04 |
