For Stratix® IV GX devices, the ALTGX MegaWizard® Plug-in Manager provides an option to select two-symbol byte ordering for basic double-width configuration. This option is available in the Rate Matcher/Byte Order screen.
When you simulate the Stratix® IV GX transceiver instance in the above configuration, the expected behavior is that the
rx_ byteorderalignstatus output port should get asserted if the received data matches both the MSByte and LSByte of programmed byte ordering pattern.
Altera has identified that in Quartus® II software version 8.0, for the basic double width mode configuration with two symbol byte ordering option enabled, the
rx_byteorderalignstatus port is asserted if the LSByte of the programmed byte ordering pattern is received irrespective of the value on the MSByte