FX3:software CPU reset and current consumption

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NXTY_Nagata
Level 4
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Distributor - NEXTY (Japan)
5 solutions authored First solution authored 100 sign-ins

Hi,

I have two questions about fx3.

Q1: When the CPU is done by software CPU resets(not whole device reset) , are the status of all I/O pins retained?

Q2: What is the maximum current consumption in the following cases?
 1.current consumption while RESET# is Low
 2.current consumption during RESET RECOVERY TIME

NXTY_Nagata_0-1632468079418.png

Regards,

Nagata.

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1 Solution
Pablo_EG
Moderator
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First question asked 250 sign-ins 250 replies posted

Hello, Nagata san,

Responding to Q2)
->The current consumption shall not exceed the values provided in Table 8 of the datasheet:

CurrentConsumption.png

Therefore the current through VDD + AVDD is < 200 mA
and the current through the USB voltage supply is < 60 mA
When sizing the LDO, please take these values as a reference.

Best regards,
Pablo

 

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6 Replies
Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi,

Can you please elaborate more about exactly when are you resetting the FX3? After execution of the firmware or during the transition time? Because if CPU reset is done after execution, it runs the same code again. In that case, all I/O pins will change according to your firmware.

Regards

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NXTY_Nagata
Level 4
Level 4
Distributor - NEXTY (Japan)
5 solutions authored First solution authored 100 sign-ins

Hi,

Thank you for your reply.

What I wanted to ask was the reset after the F/W run.
When the CPU is reset by software reset, are the internal registers initialized?
If the internal registers are not initialized, I think the GPIOs state does not change before and after the reset.
Because registers are already set by F/W that was first started.

The whole device reset case, it is the same as H/W reset, so I think ,in this case, it is expected to enter the tri-state immediately after the reset.
Am i thinking right?

Regards,
Nagata.

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi,

Can you please confirm whether isWarmReset is set in the CyU3PDeviceReset API?

Also, please let us know for what purpose you need information about maximum current consumption while RESET# is low and in recovery time?

Regards

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NXTY_Nagata
Level 4
Level 4
Distributor - NEXTY (Japan)
5 solutions authored First solution authored 100 sign-ins

Hi,

Thank you for your support.

I do not actually evaluate FX3 yet. I just wanted to see if the software-reset would change the status of all I/O-pins.

And I want to check the current capacity during start up and use it for considering the current capacity of LDO.

Regards,

Nagata

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Pablo_EG
Moderator
Moderator
Moderator
First question asked 250 sign-ins 250 replies posted

Hello, Nagata san,

Responding to Q1)
-> Yes, the state of the I/O pins is retained in CPU reset. This is not the case for the whole device reset.

Best regards,
Pablo

 

 

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Pablo_EG
Moderator
Moderator
Moderator
First question asked 250 sign-ins 250 replies posted

Hello, Nagata san,

Responding to Q2)
->The current consumption shall not exceed the values provided in Table 8 of the datasheet:

CurrentConsumption.png

Therefore the current through VDD + AVDD is < 200 mA
and the current through the USB voltage supply is < 60 mA
When sizing the LDO, please take these values as a reference.

Best regards,
Pablo

 

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