与Spartan-6上的BUFGMUX输入的连接非常有限。
对于任何给定的BUFGMUX，只有少量（大约4个）时钟输入可以到达MUX - 这些在Sparan-6用户指南UG387图1-3和1-4（及其附近的表格）中有记录。
如果你的两个时钟不在同一个BUFGMUX的I0和I1输入端，那么你就不能将它们（直接）复用在一起。
DCM / PLL输出和BUFGMUX输入之间的连接更加稳健，但仍然不完整。
器件上半部分的PLL / DCM可以达到32个BUFG的前16个，底部的DCM / PLL可以到达底部的DCM / PLL。
时钟输入可以达到哪个PLL以及哪个DCM更加复杂和混乱的限制！
所有这些限制都在UG387中详细说明。
它们很复杂，因此您需要阅读本节（介于3到17次之间）以确保您理解它们。
只有这样你才能弄清楚这个MUX是否可以完成。
显然你现在正在做什么（一个是PLL而另一个是直接的）不起作用。
也许在另一个上使用DCM，或在两者上使用PLL或......
祝你好运。
Avrum
以上来自于谷歌翻译
以下为原文
The connections to the BUFGMUX inputs on the Spartan-6 are VERY limited. For any given BUFGMUX there are only a small number (around 4) clock capable inputs that can reach the MUX - these are documented in the Sparan-6 User Guide UG387 figures 1-3 and 1-4 (and the tables near them). If your two clocks are not on a pair that can reach the I0 and I1 inputs of the same BUFGMUX then you simply can't mux them together (directly).
The connections between the DCM/PLL outputs and the BUFGMUX inputs are more robust, but still not complete. The PLLs/DCMs in the top half of the device can reach the top 16 of 32 BUFGs, and the DCM/PLLs on the bottom can reach the bottom ones. The restrictions on which clock input can reach which PLL and which DCM is even more complex and confusing!
All of these restrictions are spelled out in UG387. They are complex so you will need to read this section (somewhere between 3 and 17 times) to make sure you understant them. Only then will you be able to figure out if this MUX can be done. Clearly what you are doing now (a PLL on one and direct for the other) doesn't work. Maybe with a DCM on the other one, or a PLL on both or...
Good luck.
Avrum
与Spartan-6上的BUFGMUX输入的连接非常有限。
对于任何给定的BUFGMUX，只有少量（大约4个）时钟输入可以到达MUX - 这些在Sparan-6用户指南UG387图1-3和1-4（及其附近的表格）中有记录。
如果你的两个时钟不在同一个BUFGMUX的I0和I1输入端，那么你就不能将它们（直接）复用在一起。
DCM / PLL输出和BUFGMUX输入之间的连接更加稳健，但仍然不完整。
器件上半部分的PLL / DCM可以达到32个BUFG的前16个，底部的DCM / PLL可以到达底部的DCM / PLL。
时钟输入可以达到哪个PLL以及哪个DCM更加复杂和混乱的限制！
所有这些限制都在UG387中详细说明。
它们很复杂，因此您需要阅读本节（介于3到17次之间）以确保您理解它们。
只有这样你才能弄清楚这个MUX是否可以完成。
显然你现在正在做什么（一个是PLL而另一个是直接的）不起作用。
也许在另一个上使用DCM，或在两者上使用PLL或......
祝你好运。
Avrum
以上来自于谷歌翻译
以下为原文
The connections to the BUFGMUX inputs on the Spartan-6 are VERY limited. For any given BUFGMUX there are only a small number (around 4) clock capable inputs that can reach the MUX - these are documented in the Sparan-6 User Guide UG387 figures 1-3 and 1-4 (and the tables near them). If your two clocks are not on a pair that can reach the I0 and I1 inputs of the same BUFGMUX then you simply can't mux them together (directly).
The connections between the DCM/PLL outputs and the BUFGMUX inputs are more robust, but still not complete. The PLLs/DCMs in the top half of the device can reach the top 16 of 32 BUFGs, and the DCM/PLLs on the bottom can reach the bottom ones. The restrictions on which clock input can reach which PLL and which DCM is even more complex and confusing!
All of these restrictions are spelled out in UG387. They are complex so you will need to read this section (somewhere between 3 and 17 times) to make sure you understant them. Only then will you be able to figure out if this MUX can be done. Clearly what you are doing now (a PLL on one and direct for the other) doesn't work. Maybe with a DCM on the other one, or a PLL on both or...
Good luck.
Avrum
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