DDR memory controller (MPMC)
RM0082
196/844
Doc ID 018672 Rev 1
reg_dimm_enable [0]
Enables registered DIMM operations to control the address and
command pipeline of the Memory Controller.
1'b0 - Normal operation
1'b1 - Enable registered DIMM operation.
rtt_0 [1:0]
Defines the On-Die termination resistance for all DRAM devices. The
Memory Controller can not be set for different termination values for
each chip select.
2'b00 - Termination Disabled
2'b01 - 75 Ohm
2'b10 - 150 Ohm
2'b11 - Reserved
rtt_pad_termination [1:0]
Sets the termination resistance in the Memory Controller pads. The
Memory Controller decodes this information and sets the
param_75_ohm_sel output signal accordingly. The param_75_ohm_sel
signal will be asserted if this parameter is set to 'b01 and de-asserted
otherwise. This parameter also disables the output signal tsel, an
active-high, dynamic signal which is used in the pads to enable
termination on READs. If this parameter is set to 2'b00, the tsel signal
will be held low.
2'b00 = Termination Disabled
2'b01 = 75 Ohm
2'b10 = 150 Ohm
2'b11 = Reserved
rw_same_en [0]
Enables READ/WRITE grouping as a condition when using the
placement logic to fill the command queue.
1'b0 - Disabled
1'b1 - Enabled
srefresh [0]
When this parameter is set to 1'b1, the DRAM device(s) will be placed
in self-refresh mode. For this, the current burst for the current
transaction (if any) will complete, all banks will be closed, the self-
refresh command will be issued to the DRAM, and the clock enable
signal will be de-asserted. The system will remain in self-refresh mode
until this parameter is set to 1'b0. The DRAM devices will return to
normal operating mode after the self-refresh exit time (txsr) of the
device and any DLL initialization time for the DRAM is reached. The
Memory Controller will resume processing of the commands from the
break point.
This parameter will be updated with an assertion of the srefresh_enter
pin, regardless of the behavior on the register interface. To disable self-
refresh again after a srefresh_enter pin assertion, the user will need to
clear the parameter to 1'b0.
1'b0 - Disable self-refresh mode.
1'b1 - Begin self-refresh of the DRAM devices.
Table 153.
Memory controller parameters (continued)
Parameter
Description