How to measure the effect of functional unit activation and deactivation over current consumption?

[himanshudoshi]

Hello to all,

I want to measure the effect on current consumption due to functional unit activation and deactivation. I have gone through various documents, but couldn't get any clear picture. Can anyone help me out with that?

An assembly level instructions(program code) or the procedure will be a great help.

I am using LPCXpresso 54114 board (ARM Cortex-M4).

Thanking you,

Regards

Himanshu

[Carlos_Mendoza]

Hi Himanshu,

I would recommend you to review the following application note for more information on how to enter the low power modes and measure the current consumption:

https://www.nxp.com/docs/en/application-note/AN11611.zip 

Also, you can take a look to the Table 19 in the data sheet for information about the peripheral power consumption:

https://www.nxp.com/docs/en/data-sheet/LPC5411X.pdf 

Hope it helps!

Best Regards,
Carlos Mendoza
Technical Support Engineer

[himanshudoshi]

Thank you so much for your quick reply. What I want is to measure the current variation due to functional unit activation and deactivation based on the instruction in the program.

For example, ADD R0,R1,R2 and other data processing instruction required ALU and it's a part of a functional unit. As well LDR R0,[R1,#0x1] and other memory access instruction also need a functional unit in order to successful execution. 

So, I want to know the change in the current variation, when such instruction comes into the pipeline which activates functional unit also I would like to measure the current when an instruction comes which doesn't need a functional unit or in other words functional unit deactivation.

But I am not understanding how to measure this variation in the current. Since an effect in the current due to individual instruction is difficult and we need to loop them in order to measure the current consumption.  I am using NXP  basedLPCXpresso IDE for that, which measures the current during an execution of a program. 

Regards,
Himanshu