Symphony DSP56724/DSP56725 Multi-Core Audio Processors, Rev. 0
17-4
Freescale Semiconductor
EMC Burst Buffer
.
Any access which does not use a burst buffer, does not affect the current contents of that burst buffer.
Software can manually invalidate the read buffer or write buffer by setting the corresponding control
register bit to assert the corresponding control signal to the gasket. Software is then totally responsible for
maintaining coherency on the four buffers.
When software sets the IRB0 or IRB1 bit in the ODBC register, the module will set the data left in the read
buffer of Shared Bus master [0/1] to “invalid,” and will stall any access requests from any Shared Bus
master [0/1] until all of the data in the read buffer has been invalidated. After invalidation of the read buffer
has finished, the hardware automatically clears the corresponding register bit (IRB0 or IRB1).
When software sets the IWB0 or IWB1 bit in the ODBC register, the module should store the data left in
the write buffer of Shared Bus master [0/1] into external memory, and will stall access requests from any
Shared Bus master [0/1] until all of the data in the burst buffer is written to external memory. After
invalidation of the write buffer has finished, the hardware automatically clears the corresponding register
bit (IWB0 or IWB1).
Table 17-1. External Memory X Space Burst Control
EXMBC
Action
00
Module doesn’t burst any external memory accesses inside the X address space.
01
Module only bursts external memory accesses outside of the non-burst region of X address space.
10
Module bursts any external memory accesses inside the X address space.
11
Reserved
Table 17-2. External Memory Y Space Burst Control
EYMBC
Action
00
Module does not burst any external memory access inside the Y address space.
01
Module only bursts external memory access outside the non-burst region of Y address space.
10
Module bursts any external memory accesses inside Y address space.
11
Reserved
Table 17-3. External Memory P Space Burst Control
EPMBC
Action
00
Module does not burst any external memory accesses inside the P address space.
01
Module only bursts external memory accesses outside the non-burst region of P address space.
10
Module bursts any external memory accesses inside the P address space.
11
Reserved