LTC1450L question

Hi 

I tested LTC1450 but it doesn't work.

My sequence is

1. CLR High

2. CSLSB, CSMSB, WR, LDAC High

3. D0 ~ D11 High

4. CSLSB Low

5. after 1us, WR Low

6. after 1us, WR High

7. after 1us, CSLSB High

8. after 1us, CSMSB Low

9. after 1us, WR Low

10. after 1us, WR High

11. after 1us, CSMSB High

12. after 1us, LDAC LOW

13. after 1us, LDAC High 

But Output is 0. 

what is my problem?

Thanks.