RM0082
DDR memory controller (MPMC)
Doc ID 018672 Rev 1
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With this parameter set to 'b0, the Memory Controller will not issue any
command to the DRAM devices or respond to any signal activity except
for reading and writing parameters.
Once this parameter is set to 'b1, the Memory Controller will respond to
inputs from the device. When set, the Memory Controller begins its
initialization routine. When the interrupt bit in the int_status parameter
associated with completed initialization is set, the user may begin to
submit transactions.
1'b0 - Controller is not in active mode.
1'b1 - Begin active mode for the Memory Controller.
swap_en [0]
Enables swapping of the active command for a new higher-priority
command when using the placement logic.
1’b0 - Disabled
1’b1 - Enabled
tcke [2:0]
Defines the minimum CKE pulse width, in cycles.
tcpd [15:0]
Defines the clock enable to pre-charge delay time for the DRAM
devices, in cycles.
tdal [3:0]
Defines the auto pre-charge WRITE recovery time when auto pre-
charge is enabled (ap is set), in cycles. This is defined internally as tRP
(pre-charge time)+auto pre-charge WRITE recovery time.
Not all memories use this parameter. If tDAL is defined in the memory
specification, then program this parameter to the specified value. If the
memory does not specify a tDAL time, then this parameter should be
set to tWR+tRP.
If this parameter is set to of 0x0 the Memory Controller will not function
properly when auto pre-charge is enabled.
tdll [15:0]
Defines the DRAM DLL lock time, in cycles.
temrs [2:0]
Defines the DRAM extended mode parameter set time, in cycles.
tfaw [4:0]
Defines the DRAM tFAW parameter, in cycles.
tinit [23:0]
Defines the DRAM initialization time, in cycles.
tmrd [4:0]
Defines the DRAM mode register set command time, in cycles.
tpdex [15:0]
Defines the DRAM power-down exit command period, in cycles.
tras_lockout [0]
Defines the tRAS lockout setting for the DRAM device. tRAS lockout
allows the Memory Controller to execute auto pre-charge commands
before the tras_min parameter has expired.
1’b0 - tRAS lockout not supported by memory device.
1’b1 - tRAS lockout supported by memory device.
tras_max [15:0]
Defines the DRAM maximum row active time, in cycles.
tras_min [7:0]
Defines the DRAM minimum row activate time, in cycles.
trc [4:0]
Defines the DRAM period between active commands for the same
bank, in cycles.
trcd_int [7:0]
Defines the DRAM RAS to CAS delay, in cycles
Table 153.
Memory controller parameters (continued)
Parameter
Description