MDDR Subsystem
Microsemi Proprietary UG0446 User Guide Revision 7.0
123
Double click the
MDDR Configurator
, which gives the following choices for the external memory
interface type as shown in the following image.
•
Double Data Rate:
This option must be selected to access the external DDR memories (DDR2,
DDR3 and LPDDR).
•
Soft Memory Controller:
This option must be selected to access the external memories through
SMC_FIC and soft memory controller in FPGA. For more information on using SMC_FIC mode,
refer to the
"Soft Memory Controller Fabric Interface Controller" chapter on page 312
.
Figure 57 •
Memory Interface Configuration
Select
Double Data Rate
and click
Ok
. The MSS External Memory Configurator will be displayed as
shown in the following image. Select the memory settings as described in the steps 2, 3 and 4 in the
"Design Flow Using System Builder" section on page 112
.
To access the MDDR from the FPGA fabric, select From Fabric Interface Settings and the type of
interface as AXI, single AHBLite, or two AHBLite Interfaces. On completion of the configuration, the
selected interface is exposed in SmartDesign. The user logic in the FPGA fabric can access the DDR
memory through MDDR using these interfaces.
Figure 58 •
MSS External DDR Memory Configurator
3.12.2.2 MDDR Clock Configuration
The MDDR subsystem operates on MDDR_CLK, which comes from MSS_CCC. The MDDR_CLK must
be selected as a multiple—1, 2, 3, 4, 6 or 8—of M3_CLK. This clock value can be configured through the
MSS_CCC configurator in Libero SoC, as shown in the following figure.
The maximum frequency of MDDR_CLK is 333.33 MHz.