[coreboot] FSP settings according to decode-dimms

Zvi Vered veredz72 at gmail.com
Sat Nov 10 08:47:21 CET 2018


Following is a partial output of decode-dimms:
Module Type                                     72b-SO-UDIMM
Maximum module speed                            1333 MHz
Size                                            4096 MB
Banks x Rows x Columns x Bits                   8 x 16 x 10 x 64
Ranks                                           1
SDRAM Device Width                              8 bits
Bus Width Extension                             8 bits
tCL-tRCD-tRP-tRAS                               9-9-9-24
Supported CAS Latencies (tCL)                   10T, 9T, 8T, 7T, 6T

---=== Timing Parameters ===---
Minimum Write Recovery time (tWR)               15.000 ns
Minimum Row Active to Row Active Delay (tRRD)   6.000 ns
Minimum Active to Auto-Refresh Delay (tRC)      49.125 ns
Minimum Recovery Delay (tRFC)                   260.000 ns
Minimum Write to Read CMD Delay (tWTR)          7.500 ns
Minimum Read to Pre-charge CMD Delay (tRTP)     7.500 ns
Minimum Four Activate Window Delay (tFAW)       30.000 ns

Number of SDRAM DIMMs detected and decoded: 1
Following is a partial output of dmidecode:
Handle 0x0011, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x000F
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 2048 MB
Form Factor: DIMM
Set: None
Locator: A1_DIMM0
Bank Locator: A1_BANK0
Type: DDR3
Type Detail: Unknown
Speed: 1333 MHz
Manufacturer: A1_Manufacturer0
Serial Number: A1_SerNum0
Asset Tag: A1_AssetTagNum0
Part Number: Array1_PartNumber0
Rank: Unknown
Configured Clock Speed: 1066 MHz
Minimum Voltage: 1.35 V
Maximum Voltage: 1.5 V
Configured Voltage: 1.35 V
According to the above output I set the following in BCT:

Enable Memory Down: Disabled
DRAM Speed: 1333
DIMM 0 Enable: Enabled
DIMM 1 Enabled: Disabled
DIMM_DWidth: x8
DIMM Density: 4 Gbit
DIMM_BusWidth: 8 bits
DIMM_Sides: 1 Ranks
tCL: 9
tRP_tRCD: 9
tWR: 15
tWTR: 7
tRRD: 6
tRTP: 7
tFAW:  30

I set DIMM_Density according to DDR's datasheet (MEM4G08D3E/FABG)

Can you please tell if my settings are correct ?
tWTR = 7.5nsec. but BCT gets only integer value.
tRTP = 7.5nsec but BCT gets only integer value.
Configured Clock Speed: 1066 MHz. Is this the speed I should set ?

Thank you,
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