83Plus:Ports:8E - Revision history

Dr. D'nar: Just guessing

2013-08-14T21:20:20Z

Just guessing

Thepenguin77 at 04:22, 28 October 2011

2011-10-28T04:22:28Z

FloppusMaximus: Port 8E: pipe number

2010-11-12T03:43:19Z

Port 8E: pipe number

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[[Category:83Plus:Ports:By Address|8E - USB Pipe Number]] [[Category:83Plus:Ports:By Name|USB Pipe Number]]
== Synopsis ==
'''Port Number:''' 8Eh

'''Function:''' USB Pipe Number

This port controls which USB pipe is currently selected for I/O operations.

{{84P-Only Port|06}}

=== Read Values ===
* Always 0.

=== Write Values ===
* Pipe number (values 0 to 3 work; I'm not sure about other values.)

== Comments ==
The USB controller supports 4 (or possibly more) separate "pipes", which can be used to perform multiple USB transactions simultaneously. Pipe 0 is always used for control transactions (endpoint zero), and behaves strangely in many ways. The other pipes can be used for bulk, interrupt, and/or isochronous transactions; they are typically mapped to endpoints 1 to 3, but do not necessarily need to be.

This port has no effect on its own; it merely determines which pipe is used by subsequent I/O operations. The following ports are affected by the currently-selected pipe:
* [[83Plus:Ports:90|90]] and [[83Plus:Ports:93|93]] - maximum packet size
* [[83Plus:Ports:91|91]] and [[83Plus:Ports:94|94]] - pipe command/status
* [[83Plus:Ports:96|96]] (and possibly 97) - number of bytes received
* [[83Plus:Ports:98|98]] and [[83Plus:Ports:9A|9A]] - endpoint address and type
* [[83Plus:Ports:99|99]] and [[83Plus:Ports:9B|9B]] - polling interval

@@ Line 3: / Line 3: @@
 == Synopsis ==
 '''Port Number:''' 8Eh
 '''Function:''' USB Pipe Number

@@ Line 1: / Line 1: @@
 [[Category:83Plus:Ports:By Address|8E - USB Pipe Number]] [[Category:83Plus:Ports:By Name|USB Pipe Number]]
 == Synopsis ==
 '''Port Number:''' 8Eh
@@ Line 6: / Line 7: @@
 This port controls which USB pipe is currently selected for I/O operations.
 === Read Values ===