Hi Team,
The LPC55s69 is used as main controller in our project.
can we use USB1HS itself for two purposes i.e to serve as CDC_VCOM and as ISP peripheral during ISP bootloader mode? ....As both tasks appear independently .
Will their be any detection issue??
Any premeasure or any particular settings to be done while doing so??
Thanks & Regards
Deep_Bang
Solved! Go to Solution.
Hi Alice,
The USB detection issue solved by replacing divider circuit resistance 20k to 0k (DNI) at 'USB1_VBus'.
Thank you for the support.
BR,
Deep_Bang
Hi Alice,
The USB detection issue solved by replacing divider circuit resistance 20k to 0k (DNI) at 'USB1_VBus'.
Thank you for the support.
BR,
Deep_Bang
HI Alice,
Thank you for response
Why i raised this question is, for few fabricated boards USB detection working fine. But for few boards USB device enumeration as HID Device not happening . i.e Facing USB detection issue for few boards. PFA schematic of USB part. what could be the reason for this??
BR
Deep_Bang
Hello @Deeps_bang
Is there relationship with ISP? If do no enter ISP mode, these boards can work well?
BR
Alice
Hi Alice,
In ISP mode working fine. Detection problem in normal mode.
According to our analysis, problem might be at voltage divider circuit for USB1_VBus.
The LPC55s69 boards A0 /A1 version changes might be causing this detection issue .
for few boards detection will happen with divider ckt.
For detection error boards have plan to verify without this bias ckt.
Any input on this??
BR
Deep-Bang
Hello @Deeps_bang
1) "The LPC55s69 boards A0 /A1 version changes might be causing this detection issue ."
->> Do you mean the issue can reproduce on nxp demo board LPCxpresso55s69-evk A0/A1? If yes, you can tell me steps, I help to check on my side.
2) There is an application note, you can download and have a look:
https://www.nxp.com.cn/docs/en/application-note/TN00071.zip
BR
Alice
Hello @Deeps_bang
Yes, you can.
ISP peripheral is in ISP mode used, it means in boot rom code, while "serve as CDC_VCOM" is in your application code, they are in different stages.
BR
Alice