MSC8144E Reference Manual, Rev. 3
12-48
Freescale
Semiconductor
DDR SDRAM Memory Controller
Note:
Each command initiated through the DDR_SDRAM_MD_CNTL register should be
initiated separately in the order required by the DDR SDRAM. If more than one
command are initiated simultaneously the execution order is not guarantied and can
cause malfunction of the DDR SDRAM.
Table 12-26. DDR_SDRAM_MD_CNTL Bit Descriptions
Bit Reset
Description
Settings
MDEN
31
0
Mode Enable
Indicates that valid data is ready to write to DRAM as a
MODE REGISTER SET, EXTENDED MODE REGISTER
SET, EXTENDED MODE REGISTER SET 2, or
EXTENDED MODE REGISTER SET 3 command.
Software sets this value, and hardware clears it after the
command is issued.
Note that MD_EN, SET_REF, and SET_PRE are mutually
exclusive; they cannot be set at the same time
0
No MODE REGISTER SET,
EXTENDED MODE REGISTER
SET, EXTENDED MODE
REGISTER SET 2, or
EXTENDED MODE REGISTER
SET 3 command to be issued.
1
Valid data in the register is ready
to issue as a MODE REGISTER
SET, EXTENDED MODE
REGISTER SET, EXTENDED
MODE REGISTER SET 2, or
EXTENDED MODE REGISTER
SET 3 command.
—
30–29
0
Reserved. Write to zero for future compatibility.
CSSEL
28
0
Select for Chip Select
Specifies the chip select to drive active due to any
command forced by software in
DDR_SDRAM_MD_CNTL.
0
Chip select 0 is active.
1
Chip select 1 is active.
—
27
0
Reserved. Write to zero for future compatibility.
MDSEL
26–24
0
Mode Register Select.
Specifies the value to present to the memory bank address
pins of the DDR controller.
000
MR Mode register
001
EMR Extended Mode
Register
010
EMR2 Extended Mode
Register 2
011
EMR3 Extended Mode
Register 3
SETR
23
0
Set Refresh
Forces a refresh to the chip select specified by
DDR_SDRAM_MD_CNTL[CS_SEL]. Software sets this bit
and hardware clears it when the command is issued.
Note that MD_EN, SET_REF, and SET_PRE are mutually
exclusive; they cannot be set at the same time
0 No refresh command to issue.
1 A refresh command is ready to
issue.
SETPRE
22
0
Set Precharge All
Forces a precharge all to be issued to the chip select
specified by DDR_SDRAM_MD_CNTL[CSSEL]. Software
sets this bit, and hardware clears it when the command is
issued.
Note that MD_EN, SET_REF, and SET_PRE are mutually
exclusive; they cannot be set at the same time
0 No precharge all command to
issue.
1 A precharge all command is ready
to issue.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...