Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
406
24.7.1 SDRAMC Mode Register
Name: SDRAMC_MR
Address: 0x400E0200
Access: Read-write
Reset: 0x00000000
• MODE: SDRAMC Command Mode
This field defines the command issued by the SDRAM Controller when the SDRAM device is accessed.
31 30 29 28 27 26 25 24
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23 22 21 20 19 18 17 16
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15 14 13 12 11 10 9 8
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76543210
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MODE
Value Name Description
000 NORMAL
Normal mode. Any access to the SDRAM is decoded normally. To activate this mode,
command must be followed by a write to the SDRAM.
001 NOP
The SDRAM Controller issues a NOP command when the SDRAM device is accessed
regardless of the cycle. To activate this mode, command must be followed by a write to
the SDRAM.
010 ALLBANKS_PRECHARGE
The SDRAM Controller issues an “All Banks Precharge” command when the SDRAM
device is accessed regardless of the cycle. To activate this mode, command must be
followed by a write to the SDRAM.
011 LOAD_MODEREG
The SDRAM Controller issues a “Load Mode Register” command when the SDRAM
device is accessed regardless of the cycle. To activate this mode, command must be
followed by a write to the SDRAM.
100 AUTO_REFRESH
The SDRAM Controller issues an “Auto-Refresh” Command when the SDRAM device is
accessed regardless of the cycle. Previously, an “All Banks Precharge” command must
be issued. To activate this mode, command must be followed by a write to the SDRAM.
101 EXT_LOAD_MODEREG
The SDRAM Controller issues an “Extended Load Mode Register” command when the
SDRAM device is accessed regardless of the cycle. To activate this mode, the “Extended
Load Mode Register” command must be followed by a write to the SDRAM. The write in
the SDRAM must be done in the appropriate bank; most low-power SDRAM devices use
the bank 1.
110 DEEP_POWERDOWN Deep power-down mode. Enters deep power-down mode.