Answers Database
NGDBUILD: Error:basnu:138 - output pad net has multiple drivers
Record #6474
Product Family: Software
Product Line: FPGA Implementation
Product Part: ngdbuild
Product Version: 1.5is2
Problem Title:
NGDBUILD: Error:basnu:138 - output pad net has multiple drivers
Problem Description:
Urgency: Standard
General Description: When implementing a tri-state bus the following error may occur:
Error:basnu:138 - output pad net has multiple drivers
This error can occur if implementing a tri-state bus using LogiBLOX module type
Inputs/Outputs. This module is generated using 3-state output buffers with active
high output enables (OBUFE). However, the hardware does not support connecting
multiple OBUFEs together, as the OBUFE drives the output pad directly.
Solution 1:
To use LogiBLOX to generate the correct tri-state implementation, select the module typeTristate
Buffers. This is implemented uses internal 3-state buffers (BUFE). Then connect the output of the
BUFEs through an output buffer (OBUF) to an output pad (OPAD).
This can also be accomplished by using either the BUFE (active high enable) or
BUFT (active low enable) primitives directly, then following the same procedure given above.
End of Record #6474 - Last Modified: 06/14/99 15:15 |
