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Shared Memory Support
shared memories include additional logic to handle the mutual exclusion. The interaction
between hardware and software lockable shared memories is shown in the figure below: .
The red circle in the figure above represents a lock token. This token may be passed to any
shared memory object, regardless of whether it is implemented in hardware or software.
The dashed circle represents lock placeholders and signifies that lock can be passed to the
block it is associated with. The diamond in the figure above represents a modifiable token.
This token illustrates that when hardware has lock of the memory, the hardware shared
memory image may be modified. Likewise, when a software shared memory object has
lock, the software shared memory image may be modified.
Having two shared memory images requires synchronization between software and
hardware to ensure the images are coherent. This synchronization is accomplished by
transferring the memory image between software and hardware upon lock transfer.
System Generator for DSP User Guide
UG640 (v 14.2) July 25, 2012
www.xilinx.com
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