VHDL Advanced Features Buses Access Type File Input/Output

Reminder and extension on VHDL Advanced Features

disconnect and guarded disconnect and guarded Disconnection specifications - used to disconnect drivers from a guarded signal (register or bus). Register signals: the resolution function is not called when all sources are disconnected. Bus signals: the resolution function is called even when all sources are disconnected.

Bus example Bus signals: the resolution function is called even when all sources are disconnected.

Bus example- process equivalent to bus assignment

Access Types dynamic data types - memory allocation during run time useful for high-level behavioral modeling or hardware/software system modeling allocation is done using reserved word new followed by the data type for each access type A, a deallocation procedure is automatically defined procedure Deallocate(P: inout A); Examples

Access Types

File type and I/O

Sources Krzysztof Kuchcinski