W5300 phy and transformer


recently I have met a question about the W5300, When I debug the board which our hardware engineer designed before, I have found the transformer is pulse electronics’ 1000B-5001FX. but the W5300 supports 10BaseT/100BaseTX only. What makes me confuse is weather it works well under this condition(the transformer is 1000 and the W5300 is 10 or 100)?
At this momemt I have connect the W5300 with the PC by a ethernet cable, but there is no any response after I pluged in the jack. IS it nomal?

I would very appriate if someone could help me!