changing output drive strength of extended mode register(EMR) in MDDR

[geethar]

How to change the output drive strength of mddr in imx2333?

which hardware register concerned with changing  the output drive strength of mddr in imx233?

I want to change it  full strength and half strength to find out the performance of device.

[Yuri]

  According to the MT46H32M16LFBF  Datasheet, Extended Mode Register (EMR)

controls in particular drive strength. The EMR is programmed via the LOAD MODE REGISTER
command with BA0 = 0 and BA1 = 1. EMR bits 5,6,7 define memory drive strength.

< http://www.micron.com/~/media/Documents/Products/Data%20Sheet/DRAM/Mobile%20DRAM/Low-Power%20DRAM/LP... >

IMX23 provides EMR writing via setting bit field HW_DRAM_CTL38 [EMRS1_DATA] and

setting HW_DRAM_CTL09 [ WRITE_MODEREG ].

Have a great day,
Yuri

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[geethar]

I wanted to set the value 0x21 in EMR register.

can i  set the value to HW_DRAM_CTL38 [EMRS1_DATA] fileld?

[Yuri]

Yes

[geethar]

IN EMR register

I am setting BA1,BA0=10

drivestrength= halfstrength

partial array =full array

In EMR register ,address bus is mentioned like A0-A8,A9-An,BA0,BA1.

In HW_DRAM_CTL38 [EMRS1_DATA] fileld is a 12-bit field.

if  i take this EMR register as a 16-bit register , where the  BA0,BA1 bits occupy its position in 16 bit register?

In address bus A9-An whether n is a reference to the row selection or column selection?

[Yuri]

Only low 12 bits of EMRS should be set for any of EMRS1_DATA or EMRS2_DATA bit fields.
Note, the i.MX23 uses fields EMRS1 and EMRS2 as provided in DDR2 specs (BA1=0, BA0=1 for EMRS1),
therefore  for Your mDDR the EMRS2 field of the i.MX23 should be applied (BA1=01, BA0=0),

assuming EMRS content (bits 5,6,7) legal for MT46H32M16LFBF.

Also, please let me remind, according to section 12.2.6.7 (Mobile DDR Devices)
of the i.MX23 Reference Manual :

“When using a mobile device, the HW_DRAM_CTL05_EN_LOWPOWER_MODE bit field must be set

to 1. This enables the memory controller to use the initialization sequence and EMRS addressing appropriate

to mobile devices. When the EN_LOWPOWER_MODE bit field is cleared to 0, a standard DDRSDRAM

device may be used”.

Have a great day,
Yuri

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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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[geethar]

I am using two chip selects(chip select 0 and chip select 1) for DDR initialization to utilize 128 MB of ram.

if i want to program EMRS2 _data fields,

Do i have to program the EMRS2_DATA_0 for chip select 0 in HW_DRAM_CTL38 and

EMRS2_DATA_1 for chip select 1 in HW_DRAM_CTL39 ?

while programming these registers only  EMRS2_DATA field of selected chip are set ,can i ignore the EMRS2_DATA of other chips and set it to reset value?

[Yuri]

Correct.