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Author Topic: usb (D+,D-)  (Read 10986 times)

yalect

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usb (D+,D-)
« on: February 12, 2014, 04:27:31 am »
Hi,
Why  usb Pins (D+,D-) is signed (+, -) ?
And At low speed rate each one of them can works like in or out  or one can works both ?
Than you
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tsybezoff

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Re: usb (D+,D-)
« Reply #1 on: February 12, 2014, 05:29:40 am »
this is differential buses. Its work in an antiphase with the same data, but when have EOF (end-of-frame) buses "meet" with each other.
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Jan Axelson

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Re: usb (D+,D-)
« Reply #2 on: February 12, 2014, 10:02:01 am »
Yes, low, full, and high speeds all use differential signaling. Differential zero is when D+ is logic low and D- is logic high. Differential one is when D+ is logic high and D- is logic low. Data travels in one direction at a time.
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yalect

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Re: usb (D+,D-)
« Reply #3 on: March 19, 2014, 06:59:39 am »
thank you Jan Axelson, I understand that each of D+ and D- works like out or in for type of transfer from begining at numeration, will not change after, and which Usually of them is in and other is out ?
thank you
« Last Edit: March 19, 2014, 01:22:07 pm by yalect »
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