Digi NS9215 - Manual (Page 233)

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M E M O R Y C O N T R O L L E R
Control register
www.digiembedded.com 233
Register bit
assignment
Bits Access Mnemonic Description
D31:03 N/A Reserved N/A (do not modify)
D02 R/W LPM Low-power mode
0
Normal mode (reset value on reset_n)
1 Low-power mode
Indicates normal or low-power mode. Entering low-power mode
reduces memory controller power consumption. Dynamic memory
is refreshed as necessary. The memory controller returns to normal
functional mode by clearing the low-power mode bit or by power-
on reset.
If you modify this bit, be sure the memory controller is in idle state.
If you modify the L bit, be aware of these conditions:
The external memory cannot be accessed in low-power or
disabled state. If a memory access is performed in either of these
states, an error response is generated.
The memory controller AHB programming port can be accessed
normally.
The memory controller registers can be programmed in low-
power and/or disabled state.
D01 R/W ADDM Address mirror
0 Normal memory map
1 Reset memory map. Static memory chip select 1 is mirrored onto
chip select 0 and chip select 4 (reset value on
reset_n )
Indicates normal or reset memory map. On power-on reset, chip
select 1 is mirrored to both chip select 0 and chip select 1/chip
select 4 memory areas. Clearing the M bit allows chip select 0 and
chip select 4 memory to be accessed.
D00 R/W MCEN Memory controller enable
0 Disabled
1 Enabled (reset value on reset_n)
Disabling the memory controller reduces power consumption.
When the memory controller is disabled, the memory is not
refreshed. The memory controller is enabled by setting the enable
bit or by power-on reset.
If you modify this bit, be sure the memory controller is in idle state.
If you modify the E bit, be aware of these conditions:
The external memory cannot be accessed in low-power or
disabled state. If a memory access is performed in either of these
states, an error response is generated.
The memory controller AHB programming port can be accessed
normally.
The memory controller registers can be programmed in low-
power and/or disabled state.