Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

lpm_fifo instatiation: Logic Elements not consumed

Hello, I am using the Megawizard module lpm_fifo in my design which gave me strange problem. I have a lpm_fifo in my design whose output (8 bits) q_o[7..0] is routed to another module. ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

To dropdown the problem to the minimum level,

A quartus II project with a lpm_fifo (64 bytes) instatiated in top level .bdf with fifo output (q[7..0]) connected to a output pin is consuming 647 LE which is acceptable as it needs 512 LEto store 64 bytes (64 * 8).

Whereas, fifo output (q[7..0]) left with no connection or just connected with a bus is consuming only 20 LE

anybody had this problem before???

i have attached the complete project if anybody wants to give a try. by the way, i am working on quartus ii 8.1 build 163 web edition. device selected is maxii 1270 series cpld.

Thanks