Dsp Subsystem External Memory Connections - Texas Instruments OMAP5910 Reference Manual

Figure 18.

DSP Subsystem External Memory Connections

SPRU890A
3) The MMU checks its translation look-aside buffer (TLB, section 6.2.2) for
a match on the virtual address tag. If there is a TLB hit and the correct
access permissions for the type of access (read or write) are found, the
MMU translates the virtual address from the EMIF into a physical address
and forwards the request to the traffic controller with the appropriate
endianess conversion.
If the virtual address tag is not found, the MMU uses its table walking logic
to fetch the translation from translation tables and updates the TLB. If
correct access permissions are found, the MMU carries out the
virtual-to-physical address translation and forwards the request to the
traffic controller. If the correct access permissions are not found, MMU
generates an interrupt to the MPU core and stalls the DSP EMIF until the
error is cleared. When the MPU core clears this error, the DSP MMU
repeats this entire step.
4) The traffic controller accesses the actual OMAP resource.
Figure 18 shows the major blocks involved during an access to DSP external
memory by the DSP subsystem.
OMAP device
DSP subsystem
Requestors
DMA
DSP core
data buses
DSP core
program buses
DSP External Memory Interface
DSP MMU
Addr. Addr.
Address
conversion
Data Data
Endianess
conversion
Access
checking
Resources
IMIF
Internal
SRAM
Traffic
controller
EMIFS
Flash
EMIFF
SDRAM
DSP Subsystem 59