why the cs0 and cs1' wave in in an495 don't agree with the IDE manual?

http://space.ednchina.com/Upload/Blog/2009/03/20/d45fb86e-47c5-4ba9-bafb-bddf1f680d7d.jpg

In the manual ,to acess the cmd reg,we should assert the cs0 and negate cs1,it should like following

http://space.ednchina.com/Upload/Blog/2009/03/20/c90a3c3f-e2e9-4747-aa19-fc65f7c650f0.jpg