GX3 Maximum Reset Time

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RaMa_4514991
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First question asked Welcome!

Greetings,

The GX3 datasheet has maximum time for RESET# assertion.  Why is this not infinite?  Shouldn't I be able to assert the reset indefinitely?

In Table 18: Trst_pu min=0ms, Max=10ms.

Under Table 20. Reset Timing Parameters: "If the system applications require using hardware reset pin, RESET#, to reset GX3 during device initialization or normal operation after VBUS pin is asserted, the above timing spec (Min = 5 μs, Max =10 ms) of RESET# should be met."

Thanks

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JayakrishnaT_76
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

 

Hello,

Please keep the maximum time for RESET# assertion to less than 10ms as mentioned in GX3 datasheet. We have seen compatibility issues with some hosts when the RESET# is driven low for more than 10ms. Such hosts will disable the port if RESET# is driven for more than 10ms ((there is no response from USB device during the enumeration flow).

However, if you would still like to hold RESET# low over 10ms, then the following sequence can be used to prevent enumeration issues:

a. Drive RESET# low for greater than 10ms

b. Make RESET# high once.

c. Drive RESET# low again for less than 10ms

d. Make RESET# high again.

Best Regards,
Jayakrishna

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1 Reply
JayakrishnaT_76
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

 

Hello,

Please keep the maximum time for RESET# assertion to less than 10ms as mentioned in GX3 datasheet. We have seen compatibility issues with some hosts when the RESET# is driven low for more than 10ms. Such hosts will disable the port if RESET# is driven for more than 10ms ((there is no response from USB device during the enumeration flow).

However, if you would still like to hold RESET# low over 10ms, then the following sequence can be used to prevent enumeration issues:

a. Drive RESET# low for greater than 10ms

b. Make RESET# high once.

c. Drive RESET# low again for less than 10ms

d. Make RESET# high again.

Best Regards,
Jayakrishna
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