
LatticeECP/EC and LatticeXP
Lattice Semiconductor
sysIO Usage Guide
8-15
Appendix A. HDL Attributes for Synplify
and Precision RTL Synthesis
Using these HDL attributes, you can assign sysIO attributes directly in your source. You will need to use the attri-
bute definition and syntax for the synthesis vendor you are planning to use. Below are a list of all the sysIO attri-
butes syntax and examples for Precision RTL Synthesis and Synplify. This section only lists the sysIO buffer
attributes for these devices. You can refer to the Precision RTL Synthesis and Synplify user manuals for a complete
list of synthesis attributes. These manuals are available through ispLEVER Software Help.
VHDL Synplify/Precision RTL Synthesis
This section lists syntax and examples for all the sysIO attributes in VHDL when using Precision RTL Synthesis or
Synplicity synthesis tools.
Syntax
Table 8-8. VHDL Attribute Syntax for Synplify and Precision RTL Synthesis
Examples
IO_TYPE
--***Attribute Declaration***
ATTRIBUTE IO_TYPE: string;
--***IO_TYPE assignment for I/O Pin***
ATTRIBUTE IO_TYPE OF portA:
SIGNAL IS “PCI33”;
ATTRIBUTE IO_TYPE OF portB:
SIGNAL IS “LVCMOS33”;
ATTRIBUTE IO_TYPE OF portC:
SIGNAL IS “LVDS25”;
Attribute
Syntax
IO_TYPE
attribute IO_TYPE: string;
attribute IO_TYPE of Pinname: signal is “IO_TYPE Value”;
OPENDRAIN
attribute OPENDRAIN: string;
attribute OPENDRAIN of Pinname: signal is “OpenDrain Value”;
DRIVE
attribute DRIVE: string;
attribute DRIVE of Pinname: signal is “Drive Value”;
PULLMODE
attribute PULLMODE: string;
attribute PULLMODE of Pinname: signal is “Pullmode Value”;
PCICLAMP
attribute PCICLAMP: string;
attribute PCICLAMP of Pinname: signal is “PCIClamp Value”;
SLEWRATE
attribute PULLMODE: string;
attribute PULLMODE of Pinname: signal is “Slewrate Value”;
FIXEDDELAY
attribute FIXEDDELAY: string;
attribute FIXEDDELAY of Pinname: signal is “Fixeddelay Value”;
DIN
attribute DIN: string; attribute DIN of Pinname: signal is “ ”;
DOUT
attribute DOUT: string; attribute DOUT of Pinname: signal is “ ”;
LOC
attribute LOC: string; attribute LOC of Pinname: signal is “pin_locations”;