Rasperry pi 4 memory geometry information

[frederick00]

Hi Everyone,

i have been trying to get information about Rasperry pi 4 memory geometry and reading Service Presence Detect using decode-dimms command.
Running decode-dimms command, that gives me an error : No EEPROM found, try loading the eeprom or at24 module.

Identifying the right I2C bus, first i enabled the i2c on rasperry pi and then run the command :

Code: Select all

sudo i2cdetect -l 

and it gave me this :

Code: Select all

i2c-1   i2c             bcm2835 I2C adapter                     I2C adapter.

I deduced my SPD is on that bus but when i run the command

Code: Select all

sudo i2cdetect -y 1 

the output is :

Code: Select all

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --     

i think the i2c driver is not loaded, how can i fix this problem? where can i find the right driver ?

Thank you.

[fruitoftheloom]

Hi Everyone,

i have been trying to get information about Rasperry pi 4 memory geometry and reading Service Presence Detect using decode-dimms command.
Running decode-dimms command, that gives me an error : No EEPROM found, try loading the eeprom or at24 module.

Identifying the right I2C bus, first i enabled the i2c on rasperry pi and then run the command :

Code: Select all

sudo i2cdetect -l 

and it gave me this :

Code: Select all

i2c-1   i2c             bcm2835 I2C adapter                     I2C adapter.

I deduced my SPD is on that bus but when i run the command

Code: Select all

sudo i2cdetect -y 1 

the output is :

Code: Select all

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --     

i think the i2c driver is not loaded, how can i fix this problem? where can i find the right driver ?

Thank you.

Is this related to you other posts ??

viewtopic.php?f=29&t=281195&p=1703108

viewtopic.php?f=63&t=280192&p=1697177#p1697177

[jdb]

I2Cdetect would report an error if the i2c driver was not loaded. You're getting no results because the Pi does not have a SPD EEPROM.

Why do you want to know what the "memory geometry" is?

[frederick00]

Hi Everyone,

i have been trying to get information about Rasperry pi 4 memory geometry and reading Service Presence Detect using decode-dimms command.
Running decode-dimms command, that gives me an error : No EEPROM found, try loading the eeprom or at24 module.

Identifying the right I2C bus, first i enabled the i2c on rasperry pi and then run the command :

Code: Select all

sudo i2cdetect -l 

and it gave me this :

Code: Select all

i2c-1   i2c             bcm2835 I2C adapter                     I2C adapter.

I deduced my SPD is on that bus but when i run the command

Code: Select all

sudo i2cdetect -y 1 

the output is :

Code: Select all

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --     

i think the i2c driver is not loaded, how can i fix this problem? where can i find the right driver ?

Thank you.

Is this related to you other posts ??

viewtopic.php?f=29&t=281195&p=1703108

viewtopic.php?f=63&t=280192&p=1697177#p1697177

a kind of, because i need to know about memory geometry but here the problem is decode-dimms command doesn't work.

[frederick00]

I2Cdetect would report an error if the i2c driver was not loaded. You're getting no results because the Pi does not have a SPD EEPROM.

Why do you want to know what the "memory geometry" is?

Thank you for the answer, where can i find information about memory geometry ?
I mean, i need to know how many Ranks and Banks and the Maximum Activate Count value.

[jdb]

But why do you need this information?

[frederick00]

But why do you need this information?

About a University Project, my question is : Target Row Refresh is enabled on the Rp4 ? and how can i check its value ?

[jdb]

The LPDDR4 standard has optional support for on-die TRR.
This is the part number for the Micron 4GB SDRAM chip:
https://www.micron.com/support/tools-an ... hv#pnlFBGA
Registration is required in order to get the datasheet for it.

As far as I'm aware, the SDRAM controller does not track row open/close counts so TRR isn't implemented.

[frederick00]

The LPDDR4 standard has optional support for on-die TRR.
This is the part number for the Micron 4GB SDRAM chip:
https://www.micron.com/support/tools-an ... hv#pnlFBGA
Registration is required in order to get the datasheet for it.

As far as I'm aware, the SDRAM controller does not track row open/close counts so TRR isn't implemented.

Thank you so so much, seriously!
One last question, i understand Rp4 doesn't implement SPD EEPROM so, of course decode-dimms doesn't work as well.
How can i check that information ? is there any command to do it ?
i'm on Rp4 Model B running linux.

[jamesh]

The LPDDR4 standard has optional support for on-die TRR.
This is the part number for the Micron 4GB SDRAM chip:
https://www.micron.com/support/tools-an ... hv#pnlFBGA
Registration is required in order to get the datasheet for it.

As far as I'm aware, the SDRAM controller does not track row open/close counts so TRR isn't implemented.

Thank you so so much, really!
One last question, i understand Rp4 doesn't implement SPD EEPROM so, of course decode-dimms doesn't work as well.
How can i check that information ? is there any command to do it ?
i'm on Rp4 Model B running linux.

No command, it's impossible to provide tools for everything thing that doesn't exist.

[frederick00]

The LPDDR4 standard has optional support for on-die TRR.
This is the part number for the Micron 4GB SDRAM chip:
https://www.micron.com/support/tools-an ... hv#pnlFBGA
Registration is required in order to get the datasheet for it.

As far as I'm aware, the SDRAM controller does not track row open/close counts so TRR isn't implemented.

Thank you so so much, really!
One last question, i understand Rp4 doesn't implement SPD EEPROM so, of course decode-dimms doesn't work as well.
How can i check that information ? is there any command to do it ?
i'm on Rp4 Model B running linux.

No command, it's impossible to provide tools for everything thing that doesn't exist.

okok i get it, thank you.