AR# 8310: EXEMPLAR 1999.1g, MAP 2.1i: GSR is connected to GND, ERROR:OldMap:928 - There is no signal on pin A0 of CY4 symbol (sourceless)
EXEMPLAR 1999.1g, MAP 2.1i: GSR is connected to GND, ERROR:OldMap:928 - There is no signal on pin A0 of CY4 symbol (sourceless)
Keyword: IFD, OFD, GSR, trim, sourceless
General Description: Customer instantiated STARTUP with a reset pin connected to GSR. Some IFD and OFD are also instantiated. The result, exemplar is connecting GSR of IFD and OFD to a common GND which connects to other logic as follows:
Since GSR is connected to GND, map trim this out as well as net connected to A0 of CY4. This result in map error: ERROR:OldMap:928 - There is no signal on pin A0 of CY4 symbol "dl_top_inst_dl_count_inst_modgen_gt_206_ix23" (output signal=dl_top_inst_dl_count_inst_modgen_gt_206_nx21). Carry mode SUB-G-F1
Other possible effect is map trimming trailing logic connected to the same GND because it is sourceless.
GSR/GTS pins on components should not be connected to other logic, unless it is GSR/GTS pin of startup block.
Exemplar will fix this in future release. Two workarounds are available: Workaround #1: Instead of instantiating IFD/OFD, instantiate IFD_NG and OFD_NG.
Workaround #2: Add the following command after read and before optimize in your .tcl file as follows: ... read $input_file_list set_attribute -name FLOATVAL -value UNCONNECTED -port .xi4xl.OFD.NETLIST.GSR set_attribute -name FLOATVAL -value UNCONNECTED -port .xi4xl.IFD.NETLIST.GSR optimize -ta xi4xl ...
Note: Change xi4xl (4000xl library) to appropriate device library.