You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@mynewt.apache.org by will sanfilippo <wi...@runtime.io> on 2017/04/07 23:32:03 UTC
DC/DC regulator enable for nrf52. Where should it go?
Hello:
I want to add some code that enables the DC/DC regulator for the nordic chips. Enabling this regulator reduces power consumption (considerably). For example, using the LDO when running from flash (cache enabled) is typically 7.4mA; using the DC/DC regulator it goes to 3.7 mA.
It would be best to turn this on as soon as possible but it should only be enabled if there is some external circuitry attached to some of the pins (see the product specifications for more details). For all the BSP’s currently in the repo, the DC/DC regulator can (and should) be enabled. GIven that there is external circuitry involved I was going to create a syscfg variable that would either exist in the BSP or be overridden by the BSP. What I am having a bit of trouble figuring out is where should the code to enable the DC/DC regulator go?
We have a choice of putting it in an existing place or doing something new. It seems to me that if we choose an exisiting place it would go in either hal_bsp_init() or hal_system_start().
Some comments about the existing functions:
hal_system_start():
* Code would only need to be modified in one place (in hw/mcu).
* This function is called after the bootloader does some work, so more power savings could be realized earlier on.
* If you build an image with no bootloader I do not think this is called.
* It might be a bit of an odd place to put this code (enabled the DC/DC regulator).
hal_bsp_init():
* This is called early on by the bootloader. It is also called by the application which is a bit confusing to me. I am not super familiar with the bootloader but unless this function exists in some place I do not see or we override bsp syscfg variables in the bootloader app, hal_bsp_init() is going to do things twice. Is this true or am I missing something?
* We would have to modify hal_bsp_init() in all the bsps.
Honestly, I am not too concerned about having to modify all the bsps that use the nordic chip if the community thinks this code belongs in hal_bsp_init().
Any comments/suggestions?
Thanks!
PS If we decide that this code should exist in hw/mcu what I would do is to create a syscfg variable in hw/mcu/nordic (or hw/mcu/nordic/nrf52xxx and hw/mcu/nordic/nrf51xxx) called MCU_DCDC_ENABLE (or some such). By default, this will be 0. All the bsp syscfg.yml files will override this setting.
Re: DC/DC regulator enable for nrf52. Where should it go?
Posted by will sanfilippo <wi...@runtime.io>.
There is a syscfg value called BOOT_LOADER that is defined by the bootloader app. I think this is sufficient. Agreed?
Will
> On Apr 10, 2017, at 9:55 AM, Sterling Hughes <st...@gmail.com> wrote:
>
> Agree- but there should be some way of easily knowing whether called by boot loader or actual system.
>
> Sterling
>
>> On Apr 10, 2017, at 6:53 PM, will sanfilippo <wi...@runtime.io> wrote:
>>
>> Thinking about this more… (which is almost never a good thing with me):
>>
>> Cortex-M MCU manufacturers produce a file called system_xxxx.c (where xxx is the name of the mcu). There is a function in that file called SystemInit. Generally, this is something that should be called as early as possible and is called in the startup code. What I am now considering doing is adding our own version of “SystemInit” as I do not think it proper to modify the system_xxx.c module unless absolutely necessary.
>>
>> To be more concise:
>>
>> * SystemInit() will still be called and will remain exactly the way it is now.
>> * Add a function in hal_system.c (which is in hw/mcu) called hal_system_init().
>> * This function will be called by the startup code after SystemInit is called.
>> * The configuration variable for DCDCEN will live in the MCU (default to 0) and will be overridden by any BSP that can support it.
>>
>> NOTE: I will comment on this in the hal_system_init() function, but this function will be called by both the bootloader and the app. If there is a case where doing something twice is undesirable that will have to be dealt with by anyone adding code to hal_system_init().
>>
>> Comments?
>>
>>> On Apr 7, 2017, at 4:50 PM, Sterling Hughes <st...@gmail.com> wrote:
>>>
>>> Hi,
>>>
>>> Couple of thoughts:
>>>
>>> - I think this function/syscfg belongs in the MCU definition, as a configuration item that can be controlled by the BSP.
>>>
>>> - I think it should be called as early as possible, so probably hal_bsp_init().
>>>
>>> - It’s a bid odd that hal_bsp_init() is the same for bootloader and running image, we should probably have an option to make this different. I’d lean to having more functionality in the image, because it’s upgradable.
>>>
>>> Sterling
>>>
>>>> On 7 Apr 2017, at 16:32, will sanfilippo wrote:
>>>>
>>>> Hello:
>>>>
>>>> I want to add some code that enables the DC/DC regulator for the nordic chips. Enabling this regulator reduces power consumption (considerably). For example, using the LDO when running from flash (cache enabled) is typically 7.4mA; using the DC/DC regulator it goes to 3.7 mA.
>>>>
>>>> It would be best to turn this on as soon as possible but it should only be enabled if there is some external circuitry attached to some of the pins (see the product specifications for more details). For all the BSP’s currently in the repo, the DC/DC regulator can (and should) be enabled. GIven that there is external circuitry involved I was going to create a syscfg variable that would either exist in the BSP or be overridden by the BSP. What I am having a bit of trouble figuring out is where should the code to enable the DC/DC regulator go?
>>>>
>>>> We have a choice of putting it in an existing place or doing something new. It seems to me that if we choose an exisiting place it would go in either hal_bsp_init() or hal_system_start().
>>>>
>>>> Some comments about the existing functions:
>>>>
>>>> hal_system_start():
>>>> * Code would only need to be modified in one place (in hw/mcu).
>>>> * This function is called after the bootloader does some work, so more power savings could be realized earlier on.
>>>> * If you build an image with no bootloader I do not think this is called.
>>>> * It might be a bit of an odd place to put this code (enabled the DC/DC regulator).
>>>>
>>>> hal_bsp_init():
>>>> * This is called early on by the bootloader. It is also called by the application which is a bit confusing to me. I am not super familiar with the bootloader but unless this function exists in some place I do not see or we override bsp syscfg variables in the bootloader app, hal_bsp_init() is going to do things twice. Is this true or am I missing something?
>>>> * We would have to modify hal_bsp_init() in all the bsps.
>>>>
>>>> Honestly, I am not too concerned about having to modify all the bsps that use the nordic chip if the community thinks this code belongs in hal_bsp_init().
>>>>
>>>> Any comments/suggestions?
>>>>
>>>> Thanks!
>>>>
>>>> PS If we decide that this code should exist in hw/mcu what I would do is to create a syscfg variable in hw/mcu/nordic (or hw/mcu/nordic/nrf52xxx and hw/mcu/nordic/nrf51xxx) called MCU_DCDC_ENABLE (or some such). By default, this will be 0. All the bsp syscfg.yml files will override this setting.
>>
Re: DC/DC regulator enable for nrf52. Where should it go?
Posted by Sterling Hughes <st...@gmail.com>.
Agree- but there should be some way of easily knowing whether called by boot loader or actual system.
Sterling
> On Apr 10, 2017, at 6:53 PM, will sanfilippo <wi...@runtime.io> wrote:
>
> Thinking about this more… (which is almost never a good thing with me):
>
> Cortex-M MCU manufacturers produce a file called system_xxxx.c (where xxx is the name of the mcu). There is a function in that file called SystemInit. Generally, this is something that should be called as early as possible and is called in the startup code. What I am now considering doing is adding our own version of “SystemInit” as I do not think it proper to modify the system_xxx.c module unless absolutely necessary.
>
> To be more concise:
>
> * SystemInit() will still be called and will remain exactly the way it is now.
> * Add a function in hal_system.c (which is in hw/mcu) called hal_system_init().
> * This function will be called by the startup code after SystemInit is called.
> * The configuration variable for DCDCEN will live in the MCU (default to 0) and will be overridden by any BSP that can support it.
>
> NOTE: I will comment on this in the hal_system_init() function, but this function will be called by both the bootloader and the app. If there is a case where doing something twice is undesirable that will have to be dealt with by anyone adding code to hal_system_init().
>
> Comments?
>
>> On Apr 7, 2017, at 4:50 PM, Sterling Hughes <st...@gmail.com> wrote:
>>
>> Hi,
>>
>> Couple of thoughts:
>>
>> - I think this function/syscfg belongs in the MCU definition, as a configuration item that can be controlled by the BSP.
>>
>> - I think it should be called as early as possible, so probably hal_bsp_init().
>>
>> - It’s a bid odd that hal_bsp_init() is the same for bootloader and running image, we should probably have an option to make this different. I’d lean to having more functionality in the image, because it’s upgradable.
>>
>> Sterling
>>
>>> On 7 Apr 2017, at 16:32, will sanfilippo wrote:
>>>
>>> Hello:
>>>
>>> I want to add some code that enables the DC/DC regulator for the nordic chips. Enabling this regulator reduces power consumption (considerably). For example, using the LDO when running from flash (cache enabled) is typically 7.4mA; using the DC/DC regulator it goes to 3.7 mA.
>>>
>>> It would be best to turn this on as soon as possible but it should only be enabled if there is some external circuitry attached to some of the pins (see the product specifications for more details). For all the BSP’s currently in the repo, the DC/DC regulator can (and should) be enabled. GIven that there is external circuitry involved I was going to create a syscfg variable that would either exist in the BSP or be overridden by the BSP. What I am having a bit of trouble figuring out is where should the code to enable the DC/DC regulator go?
>>>
>>> We have a choice of putting it in an existing place or doing something new. It seems to me that if we choose an exisiting place it would go in either hal_bsp_init() or hal_system_start().
>>>
>>> Some comments about the existing functions:
>>>
>>> hal_system_start():
>>> * Code would only need to be modified in one place (in hw/mcu).
>>> * This function is called after the bootloader does some work, so more power savings could be realized earlier on.
>>> * If you build an image with no bootloader I do not think this is called.
>>> * It might be a bit of an odd place to put this code (enabled the DC/DC regulator).
>>>
>>> hal_bsp_init():
>>> * This is called early on by the bootloader. It is also called by the application which is a bit confusing to me. I am not super familiar with the bootloader but unless this function exists in some place I do not see or we override bsp syscfg variables in the bootloader app, hal_bsp_init() is going to do things twice. Is this true or am I missing something?
>>> * We would have to modify hal_bsp_init() in all the bsps.
>>>
>>> Honestly, I am not too concerned about having to modify all the bsps that use the nordic chip if the community thinks this code belongs in hal_bsp_init().
>>>
>>> Any comments/suggestions?
>>>
>>> Thanks!
>>>
>>> PS If we decide that this code should exist in hw/mcu what I would do is to create a syscfg variable in hw/mcu/nordic (or hw/mcu/nordic/nrf52xxx and hw/mcu/nordic/nrf51xxx) called MCU_DCDC_ENABLE (or some such). By default, this will be 0. All the bsp syscfg.yml files will override this setting.
>
Re: DC/DC regulator enable for nrf52. Where should it go?
Posted by will sanfilippo <wi...@runtime.io>.
Thinking about this more… (which is almost never a good thing with me):
Cortex-M MCU manufacturers produce a file called system_xxxx.c (where xxx is the name of the mcu). There is a function in that file called SystemInit. Generally, this is something that should be called as early as possible and is called in the startup code. What I am now considering doing is adding our own version of “SystemInit” as I do not think it proper to modify the system_xxx.c module unless absolutely necessary.
To be more concise:
* SystemInit() will still be called and will remain exactly the way it is now.
* Add a function in hal_system.c (which is in hw/mcu) called hal_system_init().
* This function will be called by the startup code after SystemInit is called.
* The configuration variable for DCDCEN will live in the MCU (default to 0) and will be overridden by any BSP that can support it.
NOTE: I will comment on this in the hal_system_init() function, but this function will be called by both the bootloader and the app. If there is a case where doing something twice is undesirable that will have to be dealt with by anyone adding code to hal_system_init().
Comments?
> On Apr 7, 2017, at 4:50 PM, Sterling Hughes <st...@gmail.com> wrote:
>
> Hi,
>
> Couple of thoughts:
>
> - I think this function/syscfg belongs in the MCU definition, as a configuration item that can be controlled by the BSP.
>
> - I think it should be called as early as possible, so probably hal_bsp_init().
>
> - It’s a bid odd that hal_bsp_init() is the same for bootloader and running image, we should probably have an option to make this different. I’d lean to having more functionality in the image, because it’s upgradable.
>
> Sterling
>
> On 7 Apr 2017, at 16:32, will sanfilippo wrote:
>
>> Hello:
>>
>> I want to add some code that enables the DC/DC regulator for the nordic chips. Enabling this regulator reduces power consumption (considerably). For example, using the LDO when running from flash (cache enabled) is typically 7.4mA; using the DC/DC regulator it goes to 3.7 mA.
>>
>> It would be best to turn this on as soon as possible but it should only be enabled if there is some external circuitry attached to some of the pins (see the product specifications for more details). For all the BSP’s currently in the repo, the DC/DC regulator can (and should) be enabled. GIven that there is external circuitry involved I was going to create a syscfg variable that would either exist in the BSP or be overridden by the BSP. What I am having a bit of trouble figuring out is where should the code to enable the DC/DC regulator go?
>>
>> We have a choice of putting it in an existing place or doing something new. It seems to me that if we choose an exisiting place it would go in either hal_bsp_init() or hal_system_start().
>>
>> Some comments about the existing functions:
>>
>> hal_system_start():
>> * Code would only need to be modified in one place (in hw/mcu).
>> * This function is called after the bootloader does some work, so more power savings could be realized earlier on.
>> * If you build an image with no bootloader I do not think this is called.
>> * It might be a bit of an odd place to put this code (enabled the DC/DC regulator).
>>
>> hal_bsp_init():
>> * This is called early on by the bootloader. It is also called by the application which is a bit confusing to me. I am not super familiar with the bootloader but unless this function exists in some place I do not see or we override bsp syscfg variables in the bootloader app, hal_bsp_init() is going to do things twice. Is this true or am I missing something?
>> * We would have to modify hal_bsp_init() in all the bsps.
>>
>> Honestly, I am not too concerned about having to modify all the bsps that use the nordic chip if the community thinks this code belongs in hal_bsp_init().
>>
>> Any comments/suggestions?
>>
>> Thanks!
>>
>> PS If we decide that this code should exist in hw/mcu what I would do is to create a syscfg variable in hw/mcu/nordic (or hw/mcu/nordic/nrf52xxx and hw/mcu/nordic/nrf51xxx) called MCU_DCDC_ENABLE (or some such). By default, this will be 0. All the bsp syscfg.yml files will override this setting.
Re: DC/DC regulator enable for nrf52. Where should it go?
Posted by Sterling Hughes <st...@gmail.com>.
Hi,
Couple of thoughts:
- I think this function/syscfg belongs in the MCU definition, as a
configuration item that can be controlled by the BSP.
- I think it should be called as early as possible, so probably
hal_bsp_init().
- It\u2019s a bid odd that hal_bsp_init() is the same for bootloader and
running image, we should probably have an option to make this different.
I\u2019d lean to having more functionality in the image, because it\u2019s
upgradable.
Sterling
On 7 Apr 2017, at 16:32, will sanfilippo wrote:
> Hello:
>
> I want to add some code that enables the DC/DC regulator for the
> nordic chips. Enabling this regulator reduces power consumption
> (considerably). For example, using the LDO when running from flash
> (cache enabled) is typically 7.4mA; using the DC/DC regulator it goes
> to 3.7 mA.
>
> It would be best to turn this on as soon as possible but it should
> only be enabled if there is some external circuitry attached to some
> of the pins (see the product specifications for more details). For all
> the BSP\u2019s currently in the repo, the DC/DC regulator can (and
> should) be enabled. GIven that there is external circuitry involved I
> was going to create a syscfg variable that would either exist in the
> BSP or be overridden by the BSP. What I am having a bit of trouble
> figuring out is where should the code to enable the DC/DC regulator
> go?
>
> We have a choice of putting it in an existing place or doing something
> new. It seems to me that if we choose an exisiting place it would go
> in either hal_bsp_init() or hal_system_start().
>
> Some comments about the existing functions:
>
> hal_system_start():
> * Code would only need to be modified in one place (in hw/mcu).
> * This function is called after the bootloader does some work, so more
> power savings could be realized earlier on.
> * If you build an image with no bootloader I do not think this is
> called.
> * It might be a bit of an odd place to put this code (enabled the
> DC/DC regulator).
>
> hal_bsp_init():
> * This is called early on by the bootloader. It is also called by the
> application which is a bit confusing to me. I am not super familiar
> with the bootloader but unless this function exists in some place I do
> not see or we override bsp syscfg variables in the bootloader app,
> hal_bsp_init() is going to do things twice. Is this true or am I
> missing something?
> * We would have to modify hal_bsp_init() in all the bsps.
>
> Honestly, I am not too concerned about having to modify all the bsps
> that use the nordic chip if the community thinks this code belongs in
> hal_bsp_init().
>
> Any comments/suggestions?
>
> Thanks!
>
> PS If we decide that this code should exist in hw/mcu what I would do
> is to create a syscfg variable in hw/mcu/nordic (or
> hw/mcu/nordic/nrf52xxx and hw/mcu/nordic/nrf51xxx) called
> MCU_DCDC_ENABLE (or some such). By default, this will be 0. All the
> bsp syscfg.yml files will override this setting.