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AR# 774

XC5200: Mode pins M0, M1, M2 are bidirectional, but library MD0, MD1, MD2 are unidirectional.


Keywords: MD0, MD1, MD2, IOs, 5200

Urgency: Standard


The 5200 mode pins are all io's after configuration, but if you use the MD0, MD1
or MD2 library symbols to define your mode pins then you can only use the pin
as a unidirectional pin. The reason for this is that the MD0, MD1 and MD2 library
symbols were only intended for design conversions from the XC4000 devices,
therefore these pins would not be bidirectional.

If you use these symbols as a bidirectional io then XNFPREP will issue an eror
saying that these symbols can only be used as unidirectional signals.


Don't use the special MD0, MD1 and MD2 library symbols when trying to use the
mode pins as bidirectional io's. Use a regular iopad symbol and lock that symbol
to the appropiate mode pin.
AR# 774
日期 09/05/1997
状态 Archive
Type 综合文章