Originally Posted by AMD spam posts
Field Descriptions
CKE Drive Strength (CkeDrvStren)—Bits 1–0. This field is used to select the drive strength of the
CKE pins.
00b = 1.0x.
01b = 1.25x
10b = 1.5x (Default)
11b = 2.0x
CS/ODT Drive Strength (CsOdtDrvStren)—Bits 5–4. This field is used to select the drive strength
of the CS and ODT pins.
00b = 1.0x.
01b = 1.25x
10b = 1.5x (Default)
11b = 2.0x
Address/Command Drive Strength (AddrCmdDrvStren)—Bits 9–8. This field is used to select the
drive strength of the address, RAS, CAS, WE, bank and parity pins.
00b = 1.0x.
01b = 1.25x
10b = 1.5x (Default)
11b = 2.0x
MEMCLK Drive Strength (ClkDrvStren)—Bits 13–12. This field is used to select the drive
strength of the MEMCLK pins.
00b = 0.75x.
01b = 1.0x (Default)
10b = 1.25x
11b = 1.5x
Data Drive Strength (DataDrvStren)—Bits 17–16. This field is used to select the drive strength of
the Data pins.
00b = 0.75x.
01b = 1.0x (Default)
10b = 1.25x
11b = 1.5x
DQS Drive Strength (DqsDrvStren)—Bits 21–20. This field is used to select the drive strength of
the DQS pins.
00b = 0.75x.
01b = 1.0x (Default)
10b = 1.25x
11b = 1.5x
Note: The DM[8:0] and DQS[17:9] functions share pins on the DIMM connector. The function
selection is applied based on whether the DIMM is populated with by-4 (x4) DRAM devices,
in which case the DQS[17:9] function is applied, or not (x8 or x16 DRAM devices), in which
case the DM[8:0] function is applied. However, the DM function is associated with the data
pin group and should therefore be controlled DataDrvStren. While the processor supports
concurrent population of x4 and non-x4 DIMMs, the determination as to which field controls
the drive strength of these pins is applied statically based on these rules:
- If all DIMMs of a channel are populated with non-x4 devices, DataDrvStren is applied.
- If any DIMMs of a channel is populated with x4 devices, DqsDrvStren is applied.
Processor On-die Termination (ProcOdt)—Bits 29–28. This field is used to select the resistance of
the on-die termination resistors.
00b = 300 ohms +/- 20%
01b = 150 ohms +/- 20%.
10b = 75 ohms +/- 20%.
11b = Reserved.