83Plus:Ports:57 - Revision history

Thepenguin77 at 04:15, 28 October 2011

2011-10-28T04:15:40Z

FloppusMaximus at 22:13, 5 September 2010

2010-09-05T22:13:33Z

FloppusMaximus: Port 57 - line event mask

2010-09-05T22:11:35Z

Port 57 - line event mask

New page

[[Category:83Plus:Ports:By Address|57 - USB Line Event Mask]] [[Category:83Plus:Ports:By Name|USB Line Event Mask]]
== Synopsis ==
'''Port Number:''' 57h

'''Function:''' USB Line Event Mask

This port controls whether interrupts should be generated when the USB lines change.

{{84P-Only Port|16}}

=== Read Values ===
* Bit 0: Set if D+-low events are enabled.
* Bit 1: Set if D+-high events are enabled.
* Bit 2: Set if D?-low events are enabled.
* Bit 3: Set if D?-high events are enabled.
* Bit 4: Set if ID-low events are enabled.
* Bit 5: Set if ID-high events are enabled.
* Bit 6: Set if Vbus-high events are enabled.
* Bit 7: Set if Vbus-low events are enabled.

=== Write Values ===
* Bit 0: Set to allow D+-low events.
* Bit 1: Set to allow D+-high events.
* Bit 2: Set to allow D?-low events.
* Bit 3: Set to allow D?-high events.
* Bit 4: Set to allow ID-low events.
* Bit 5: Set to allow ID-high events.
* Bit 6: Set to allow Vbus-high events.
* Bit 7: Set to allow Vbus-low events.

== Comments ==
This port allows you to trigger an interrupt when one of the USB lines changes from high to low, or low to high. For instance, if bit 6 of this port is set, an interrupt is generated when the Vbus line goes from low to high.

When such an interrupt occurs, [[83Plus:Ports:55|port 55]] bit 2 will be cleared, and [[83Plus:Ports:56|port 56]] will indicate which event(s) caused the interrupt. To acknowledge the interrupt, clear the appropriate bit of port 57.

An interrupt only occurs if the line changes while the corresponding bit of this port is set (e.g., if Vbus is already high, and you set bit 6, nothing will happen - Vbus would have to go low and then high again for an interrupt to be generated.)

@@ Line 1: / Line 1: @@
 [[Category:83Plus:Ports:By Address|57 - USB Line Event Mask]] [[Category:83Plus:Ports:By Name|USB Line Event Mask]]
 == Synopsis ==
 '''Port Number:''' 57h
@@ Line 6: / Line 7: @@
 This port controls whether interrupts should be generated when the USB lines change.
 === Read Values ===

@@ Line 12: / Line 12: @@
 * Bit 0: Set if D+-low events are enabled.
 * Bit 1: Set if D+-high events are enabled.
-* Bit 2: Set if D?-low events are enabled.
+* Bit 2: Set if D&#8722;-low events are enabled.
-* Bit 3: Set if D?-high events are enabled.
+* Bit 3: Set if D&#8722;-high events are enabled.
 * Bit 4: Set if ID-low events are enabled.
 * Bit 5: Set if ID-high events are enabled.
@@ Line 22: / Line 22: @@
 * Bit 0: Set to allow D+-low events.
 * Bit 1: Set to allow D+-high events.
-* Bit 2: Set to allow D?-low events.
+* Bit 2: Set to allow D&#8722;-low events.
-* Bit 3: Set to allow D?-high events.
+* Bit 3: Set to allow D&#8722;-high events.
 * Bit 4: Set to allow ID-low events.
 * Bit 5: Set to allow ID-high events.