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SYSCFG Registers
10.4.19 DDR Slew Register (DDR_SLEW)
The DDR slew register (DDR_SLEW) reflects the DDR I/O timing as programmed in the device eFuse.
The CMOSEN field configures the DDR I/O cells into an LVCMOS buffer (this makes it mDDR
compatible). The DDR_SLEW is shown in
and described in
Figure 10-46. DDR Slew Register (DDR_SLEW)
31
16
Reserved
R-0
15
12
11
10
9
8
Reserved
ODT_TERMON
ODT_TERMOFF
R-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
Reserved
DDR_PDENA
CMOSEN
DDR_DATASLEW
DDR_CMDSLEW
R-0
R/W-0
R/W-0
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 10-50. DDR Slew Register (DDR_SLEW) Field Descriptions
Bit
Field
Value
Description
31-12
Reserved
0
Reserved
11-10
ODT_TERMON
Controls Thevenin termination mode while I/O is in read or write mode. Termination is not
supported on this device.
0
No termination
1h-3h
Reserved
9-8
ODT_TERMOFF
Controls Thevenin termination mode while I/O is not in read or write mode. Termination is
not supported on this device.
0
No termination
1h-3h
Reserved
7-6
Reserved
0
Reserved
5
DDR_PDENA
Enables pull downs for mDDR mode (should be disabled for DDR2).
0
Pull downs are disabled. Disable pull downs when using DDR2.
1
Pull downs are enabled. Enable pull downs when using mDDR.
4
CMOSEN
Selects mDDR LVCMOS RX / SSTL18 differential RX.
0
SSTL Receiver. Select SSTL when using DDR2.
1
LVCMOS Receiver. Select LVCMOS when using mDDR.
3-2
DDR_DATASLEW
Slew rate mode control status for data macro. Slew rate control is not supported on this
device.
0
Slew rate control is off.
1h-3h
Reserved
1-0
DDR_CMDSLEW
Slew rate mode control status for command macro. Slew rate control is not supported on
this device.
0
Slew rate control is off.
1h-3h
Reserved
212
System Configuration (SYSCFG) Module
SPRUGX5A
–
May 2011
Copyright
©
2011, Texas Instruments Incorporated