User Manual
Datasheet 57
Electrical Specifications
V
OH
Output High Voltage
–
V
CCD
– ((V
CCD
/ 2)*
(R
ON
/
(R
ON
+R
VTT_TERM
))
– V 2, 5, 7
Data Signals
V
OL
Output Low Voltage – Varies – 10
V
OH
Output High Voltage – V
CCD
–
Reference Clock Signal
R
ON
DDR4 Clock Buffer
On Resistance
27 – 33 ohm 6
Command Signals
R
ON
DDR4 Command Buffer
On Resistance
16 – 20 ohm 6
R
ON
DDR4 Reset Buffer
On Resistance
– 78 – ohm 6
V
OL_CMOS1.2V
Output Low
Voltage, Signals
DDR_RESET_ C{01/23}_N
– – 0.2*V
CCD
V 1, 2
V
OH_CMOS1.2V
Output High
Voltage, Signals
DDR_RESET_ C{01/23}_N
0.9*V
CCD
––V 1, 2
Control Signals
R
ON
DDR4 Control Buffer
On Resistance
27 – 33 ohm 6
DDR4 Miscellaneous Signals
ALERT_N
On-Die Termination
for Parity Error Signals
81 90 99 ohm
V
IL
Input Low Voltage
DRAM_PWR_OK_C{01/23}
– – 304 mV 2, 3
V
IH
Input High Voltage
DRAM_PWR_OK_C{01/23}
800 – mV 2, 4, 5
Notes:
1. Unless otherwise noted, all specifications in this table apply to all processor frequencies.
2. The voltage rail V
CCD
which will be set to 1.2V nominal depending on the voltage of all DIMMs connected to the processor.
3. V
IL
is the maximum voltage level at a receiving agent that will be interpreted as a logical low value.
4. V
IH
is the minimum voltage level at a receiving agent that will be interpreted as a logical high value.
5. V
IH
and V
OH
may experience excursions above V
CCD
. However, input signal drivers must comply with the signal quality
specifications.
6. This is the pull down driver resistance. Reset drive does not have a termination.
7. R
VTT_TERM
is the termination on the DIMM and not controlled by the processor. Refer to the applicable DIMM datasheet.
8. The minimum and maximum values for these signals are programmable by BIOS to one of the pairs.
9. Input leakage current is specified for all DDR4 signals.
10. Vol = Ron * [VCCD/(Ron + Rtt_Eff)], where Rtt_Eff is the effective pull-up resistance of all DIMMs in the system, including
ODTs and series resistors on the DIMMs.
Table 5-14. DDR4 Signal DC Specifications (Sheet 2 of 2)
Symbol Parameter Min Nom Max Units Notes
1