Difference between revisions of "83Plus:Ports:8F"
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[[Category:83Plus:Ports:By Address|8F - VBus Control]] [[Category:83Plus:Ports:By Name|VBus Control]] | [[Category:83Plus:Ports:By Address|8F - VBus Control]] [[Category:83Plus:Ports:By Name|VBus Control]] | ||
| − | {{84P-Only Port| | + | {{84P-Only Port|07}} |
== Synopsis == | == Synopsis == | ||
'''Port Number:''' 8F | '''Port Number:''' 8F | ||
Revision as of 20:23, 27 October 2011
| This port only exists on the the TI-84 Plus and the TI-84 Plus Silver Edition. On the standard TI-83 Plus, it acts as a shadow of port 07. On the TI-83 Plus Silver Edition, this port has no effect. |
Synopsis
Port Number: 8F
Function: VBus Control
Using this port, you can control the VBus line and see its status.
Read Values
- Bit 0: Set if VBus is high. (Cutoff between 1.5 V and 3 V)
- Bit 1: Unknown. Peripheral routines like this bit.
- Bit 2: Set if calculator is host.
- Bit 3: Reset if VBus is externally powered.
- Bit 4: Set if VBus is externally powered.
- Bit 5: Always 0
- Bit 6: Set if calculator is successfully hosting a device. It gets set when the device turns on.
- Bit 7: Reset if A-Type cable is currently inserted.
Write Values
- Bit 0: Set to power VBus. This will only stick if the USB controller ports are set up correctly. Most notably port 4C and port 54.
- Bit 2: Unknown. Peripheral routines sometimes set this.
- Bits 3-7: No effect
Comments
If VBus is internally powered and you short circuit it, it will power down.
Bit 6 is pretty strange, it's not as simple as VBus high, or even VBus supplying power. I lit an LED drawing 30 mA off of VBus and port 6 stayed off. But .5 sec after I plug in a USB device, it sets itself.
