问答 #31960 - Spartan-3A/-6 Devices - Support of GTLP Input using HSTL Input Buffer
Spartan-3A/-6 Devices - Support of GTLP Input using HSTL Input Buffer
| 问答编号# | 31960 |
| 型号 | HW-SelectIO |
| 最后更新日期 | 2009-11-06 00:00:00.0 |
| 记录状态 | Active |
| 关键词 | GTLP, GTL+, HSTL |
疑问描述
Keywords: GTLP, GTL+, HSTL
How do you implement GTLP Input support in Spartan-3A or Spartan-6 devices?
解决方案
Spartan-3A and Spartan-6 devices use differential buffers for HSTL and SSTL input levels. Differential input buffers can be made compatible with GTLP switching levels by modifying the termination scheme, and adjusting VREF and VTT as per GTLP requirements.Design Requirements:
1. Select the HSTL_I or HSTL_III input buffer.
2. Connect VREF to 1.0V.
NOTE: GTLP support in Spartan-3A and Spartan-6 devices is limited to Input Only.