i.mx7 - Can Cortex-M4 run independently from Cortex-A?

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

i.mx7 - Can Cortex-M4 run independently from Cortex-A?

1,295 Views
k_schulze-dieck
Contributor I

Hi all,

I am currently evaluating if we can use the i.mx7Solo for our application. Therefore I need to know how independtly from each other the Cortex-A and Cortex-M can run.

I already found out, that the uboot can be configured so that the Cortex-M4 boots through the QUADSPI interface, meaning that both cores boot up simultaneously. But what happens to the Cortex-M4 when for example a Linux on the Cortex-A crashes and a reboot is triggered?

Will the Cortex-M be down from the moment the reboot is triggered or is the downtime much shorter, for example only the time the uboot is executed? Is my assumption right, that we will defenitly have a reset of the Cortex-M4 as well?

If somebody can also provide some examples or application nodes regarding this topic I would be very happy.

Thanks

Klaas

Labels (2)
0 Kudos
7 Replies

1,071 Views
k_schulze-dieck
Contributor I

Hi Igor,

thanks for your answer.

I still have some open points on this question. It is now clearer for me, how I can trigger a reboot of the M4 core. But I still can't see, how and when a reboot of the M4 is triggered, when I reboot the Cortex-A. When exactly and by which module will the SW_M4C_RST flag be set?

Thanks

Klaas

0 Kudos

1,071 Views
igorpadykov
NXP Employee
NXP Employee

Hi Klaas

I sent additional material to you via mail, it should clarify.

>When exactly and by which module will the SW_M4C_RST flag be set?

it is set by System Reset Controller (SRC).

Best regards
igor

0 Kudos

1,071 Views
k_schulze-dieck
Contributor I

Hi Igor

can you also say, _when_ it will be set? Inside Uboot or when 'reboot' is called inside linux?

Thanks

Klaas

0 Kudos

1,071 Views
igorpadykov
NXP Employee
NXP Employee

Hi Klaas

 

it is set during 'reboot'.

 

Best regards
igor

0 Kudos

1,071 Views
k_schulze-dieck
Contributor I

So is there some userland-application triggered, when reboot is called? How is the SRC informed, that a reboot was triggered?

0 Kudos

1,071 Views
igorpadykov
NXP Employee
NXP Employee

>How is the SRC informed, that a reboot was triggered?

it is triggered by POR or any reset event. From sect.6.2 i.MX 7Dual Applications Processor Reference Manual

"The System Reset Controller (SRC) controls the reset and boot operation of the SoC.
It is responsible for the generation of all reset signals and boot decoding."

From sect.6.2.1.1 Features

"Receives and handles the resets from all the reset sources"

Best regards
igor

0 Kudos

1,071 Views
igorpadykov
NXP Employee
NXP Employee

Hi Klaas

after reboot or POR M4 will be in default state (M4 core is kept in the reset state),

one can check Boot Chapter of Reference Manual, sect.6.2 System Reset Controller (SRC)

Table 6-9. SRC reset functionality describes M4 reset sources.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos