Столкнулся с такой проблемой. Есть FPGA Spartan 3E (XC3S250E) к которому заведена двухнапрямленая 8 бит шина данных.
D0 - P32(GCLK12)
D1 - P33(GCLK13)
D2 - P34(IO)
D3 - P35(GCLK14)
D4 - P36(GCLK15)
D5 - P38(GCLK0)
D6 - P40(GCLK2)
D7 - P41(GCLK3)
Проект Синтез проходит а вот Implement Design: MAP завершается ошибкой
Цитата
ERROR:Pack:1107 - Unable to combine the following symbols into a single IOB
component:
TBUF symbol "DataBus_5_OBUFT" (Control Signal =
DataBus_Data_Out_not0000_inv)
PAD symbol "DataBus<5>" (Pad Signal = DataBus<5>)
An IO component of type IOB was chosen because the IO contains symbols and/or
properties consistent with output or bi-directional usage and contains no
other symbols or properties that require a more specific IO component type.
Each of the following constraints specifies an illegal physical site for a
component of type IOB:
Symbol "DataBus<5>" (LOC=P38 [Physical Site Type = DIFFMI])
The component type is determined by the types of logic and the properties and
configuration of the logic it contains. Please double check that the types of
logic elements and all of their relevant properties and configuration options
are compatible with the physical site type of the constraint.
Please correct the constraints accordingly.
component:
TBUF symbol "DataBus_5_OBUFT" (Control Signal =
DataBus_Data_Out_not0000_inv)
PAD symbol "DataBus<5>" (Pad Signal = DataBus<5>)
An IO component of type IOB was chosen because the IO contains symbols and/or
properties consistent with output or bi-directional usage and contains no
other symbols or properties that require a more specific IO component type.
Each of the following constraints specifies an illegal physical site for a
component of type IOB:
Symbol "DataBus<5>" (LOC=P38 [Physical Site Type = DIFFMI])
The component type is determined by the types of logic and the properties and
configuration of the logic it contains. Please double check that the types of
logic elements and all of their relevant properties and configuration options
are compatible with the physical site type of the constraint.
Please correct the constraints accordingly.
Насколько я понимаю то проблема именно в том, что шина заведена на GCLKn. Google сказал что для Spartan 2 такой тип вывода может работать только на вход (при использовании IBUF). А вот конкретно для XC3S250E такой информации в даташити не нашел.
Есть ли какой то нормальный способ организовать двухнапрямленую шину данных в данном случае?
