Preliminary
Use Case
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2.3.4.1.3 Case 3: Two SDRAM Controllers, 1152 MB (1 GB + 128 MB) DDR Asymmetrical Distribution
NOTE:
For optimal system performance, symmetric configuration is HIGHLY recommended. Unless
dictated by system cost and other constraints, Asymmetrical distribution of memory should
not be considered.
There are many ways to configure the section mapping in this use case.
Option 1: Asymmetrical section of EMIF0 is mapped to system address C000 0000h-C7FF FFFFh, higher
portion of the SDRAM in system memory map.
Table 2-8. Section Mapping Option 1
Bit
Field
Section 0
Section 1
31-24
SYS_ADDR
80h (incoming System Address MSB)
88h (incoming System Address MSB)
22-20
SYS_SIZE
3h (128 MB)
6h (1 GB)
19-18
SDRC_INTL
0 (No interleaving)
2h (256 bytes interleaving)
17-16
SDRC_ADDRSPC
0 (Unused Reserved field)
0 (Unused Reserved field)
8
SDRC_MAP
1 (Map to EMIF0)
3h (Map to both EMIF0 and EMIF1)
7-0
SDRC_ADDR
20h (SDRC address MSB)
0 (SDRC address MSB)
Option 2: Asymmetrical section of EMIF0 is mapped to system address 8000 0000h-87FF FFFFh, Lower
portion of the SDRAM in system memory map.
Table 2-9. Section Mapping Option 2
Bit
Field
Section 0
Section 1
31-24
SYS_ADDR
80h (incoming System Address MSB)
C0h (incoming System Address MSB)
22-20
SYS_SIZE
6h (1 GB)
3h (128 MB)
19-18
SDRC_INTL
2h (256 bytes interleaving)
0 (No interleaving)
17-16
SDRC_ADDRSPC
0 (Unused Reserved field)
0 (Unused Reserved field)
8
SDRC_MAP
3h (Map to both EMIF0 and EMIF1)
1 (Map to EMIF0)
7-0
SDRC_ADDR
0 (SDRC address MSB)
20h (SDRC address MSB)
384
DMM/TILER
SPRUGX9 – 15 April 2011
© 2011, Texas Instruments Incorporated