| ??? 08/24/06 15:08 Read: times |
#122905 - 127 devices regardless of hubs Responding to: ???'s previous message |
the whole USB Bus can support 127 devices irrespective of how many hubs you have in the bus. This is the correct answer. Host controller (HC) assigns an unique 7-bit address to each device on the bus tree. This address is used in the token packet to specify the device that the HC communicates with. The address '0' is a specific address, which means the device is not addressed yet. Therefore, 127 addresses are effective. On the USB bus tree, hub works as a repeater. It only passes through packets between the HC and the device. ie. cascading hub doesn't affect this addressing scheme. Please note, hub also gets an address itself. Tsuneo |
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| 127 devices regardless of hubs | 01/01/70 00:00 | |
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