説明

In the "HSTL DCI usage examples" figure, there is no termination at the driver. However, OBUF_HSTL_I_DCI and OBUF_HSTL_III_DCI are available. What kind of termination exists in these OBUFs?

ソリューション

OBUF_HSTL_I_DCI and OBUF_HSTL_III_DCI are not performing any termination (these I/O standards do not need driver termination). 

The DCI OBUFs for these I/O standards have the same characteristic as the non-DCI OBUF. 

A termination example for HSTL DCI is shown in the Virtex-II/-II Pro User Guides -> Design Considerations -> (Using) Digitally Controlled Impedance (DCI). 

Virtex-II Pro 

http://www.xilinx.com/support/documentation/user_guides/ug012.pdf
 

Virtex-II 

http://www.xilinx.com/support/documentation/user_guides/ug002.pdf
 

Please see (Xilinx Answer 14128) for more information.