Article ID: 000087140 Content Type: Troubleshooting Last Reviewed: 08/13/2012

Why do I get compilation error when I select clk [1] through [9] as the input clock source for the ATX_PLL in the MegaWizard?

Environment

BUILT IN - ARTICLE INTRO SECOND COMPONENT
Description

The ALTGX Megawizard™ allows maximum of 10 input reference clocks as sources to the ATX_PLL. When the user selects values from 1 through to 9 for the ATX PLL in the What is the selected input clock source for the Rx/Tx PLLs? option the design fails compilation. Quartus® II software will produce an error saying for example that inclk [1] of ATX PLL cannot be connected.

The following workaround is required

- Select ‘0’ as the input clock source for the ATX PLL and

- Connect the pll_inclk_rx_cruclk [0] as the input clock source for the ATX PLL in your design

This problem occurs in Quartus II software version 9.1 and is scheduled to be fixed Quartus II software version 9.1 SP1.

Related Products

This article applies to 2 products

Stratix® IV FPGAs
Stratix® IV GX FPGA