frederick00
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:39 am

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
Posts: 24509
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:43 am

frederick00 wrote:
Wed Jul 29, 2020 10:39 am
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
Thinking outside the box is better than burying your head in the sand...

jdb
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2463
Joined: Thu Jul 11, 2013 2:37 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:46 am

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?
Rockets are loud.
https://astro-pi.org

frederick00
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:48 am

fruitoftheloom wrote:
Wed Jul 29, 2020 10:43 am
frederick00 wrote:
Wed Jul 29, 2020 10:39 am
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
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:50 am

jdb wrote:
Wed Jul 29, 2020 10:46 am
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
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2463
Joined: Thu Jul 11, 2013 2:37 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:51 am

But why do you need this information?
Rockets are loud.
https://astro-pi.org

frederick00
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 10:52 am

jdb wrote:
Wed Jul 29, 2020 10:51 am
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
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2463
Joined: Thu Jul 11, 2013 2:37 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 11:26 am

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.
Rockets are loud.
https://astro-pi.org

frederick00
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 11:32 am

jdb wrote:
Wed Jul 29, 2020 11:26 am
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.
Last edited by frederick00 on Wed Jul 29, 2020 3:31 pm, edited 1 time in total.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 27419
Joined: Sat Jul 30, 2011 7:41 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 2:46 pm

frederick00 wrote:
Wed Jul 29, 2020 11:32 am
jdb wrote:
Wed Jul 29, 2020 11:26 am
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.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

frederick00
Posts: 55
Joined: Mon Jul 13, 2020 8:38 pm

Re: Rasperry pi 4 memory geometry information

Wed Jul 29, 2020 3:31 pm

jamesh wrote:
Wed Jul 29, 2020 2:46 pm
frederick00 wrote:
Wed Jul 29, 2020 11:32 am
jdb wrote:
Wed Jul 29, 2020 11:26 am
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.

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