Fitter giving error for invalid m value for HSSI PLL loop in stratix 4 transceiver

Hi,

I am using Stratix4GX230k40C3ES device for transceiver development.But it is giving error in fitting, printing following error:

"Currently the m counters of 16 & 20 in the HSSi PLL loop have been disabled for stratix GX & GT devices.However you have currently set illegal m value"

I have checked the instantiation which i have generated, it has tx PLL m value set to 20 for i/p ref clk of 156.26Mhz & serial data rate of 6250Mbps.

One strange thing is that when i change the device to Stratix4GX230k40C3, (no Engineering sample) my design got complied fully.But when i do the programming with the generated sof file it give "CONFIG_DONE pin is not getting high"

But if i compiled the design after removing the txrx interface with Stratix4GX230k40C3ES device it get compiled & programed also.

Can anyone tell what is wrong with my code if i use Stratix4GX230k40C3ES in my design.

Thanks....