14 lines
559 B
Plaintext
14 lines
559 B
Plaintext
USB driver in Chopstx
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Full speed device is assumed. Bus powered system is assumed.
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API-wise, self powered system is not supported (yet). To support self
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powered system, we need to define the hardware interface detecting
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VBUS voltage. Only after detecting VBUS power, we can enable USB
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driver (D+/D- lines). For self powered system, driving D+/D- lines
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(by fixed pull-up resistor) violates the USB specification.
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This driver can be used without Chopstx. Please supply
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-DFREE_STANDING when used without Chopstx. An example can be find
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in gnuk/regnual.
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