Difference between revisions of "83Plus:Ports:8F"
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(Making some guesses based on the HDRC source) |
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== Synopsis == | == Synopsis == | ||
'''Port Number:''' 8F | '''Port Number:''' 8F | ||
| + | |||
| + | '''Equivalent HDRC port:''' Possibly MGC_O_HDRC_DEVCTL (0x60) | ||
'''Function:''' VBus Control | '''Function:''' VBus Control | ||
| Line 9: | Line 11: | ||
=== Read Values === | === Read Values === | ||
| − | * Bit 0: Set if VBus is high. (Cutoff between 1.5 V and 3 V) | + | * Bit 0: |
| − | * Bit 1: Unknown. Peripheral routines like this bit. | + | ** Set if VBus is high. (Cutoff between 1.5 V and 3 V) |
| − | * Bit 2: Set if calculator is host. | + | ** Possibly named MGC_M_DEVCTL_SESSION in the HDRC |
| − | * Bit 3: Reset if VBus is externally powered. | + | * Bit 1: |
| − | * Bit 4: Set if VBus is externally powered. | + | ** Unknown. Peripheral routines like this bit. |
| − | * Bit 5: Always 0 | + | ** Possibly named MGC_M_DEVCTL_HR in the HDRC |
| − | * Bit 6: Set if calculator is successfully hosting a device. It gets set when the device turns on. | + | * Bit 2: |
| − | * Bit 7: Reset if A-Type cable is currently inserted. | + | ** Set if calculator is host. |
| + | ** Possibly named MGC_M_DEVCTL_HM in the HDRC | ||
| + | * Bit 3: | ||
| + | ** Reset if VBus is externally powered. | ||
| + | ** Possibly named MGC_M_DEVCTL_VBUS in the HDRC | ||
| + | * Bit 4: | ||
| + | ** Set if VBus is externally powered. | ||
| + | ** Possibly named MGC_M_DEVCTL_VBUS in the HDRC | ||
| + | * Bit 5: | ||
| + | ** Always 0 | ||
| + | ** Possibly named MGC_M_DEVCTL_LSDEV in the HDRC | ||
| + | ** Possibly actually indicates whether the bus is in low-speed or full-speed | ||
| + | * Bit 6: | ||
| + | ** Set if calculator is successfully hosting a device. It gets set when the device turns on. | ||
| + | ** Possibly named MGC_M_DEVCTL_FSDEV in the HDRC | ||
| + | ** Possibly actually indicates whether the bus is in low-speed or full-speed | ||
| + | * Bit 7: | ||
| + | ** Reset if A-Type cable is currently inserted. | ||
| + | ** Possibly named M_DEVCTL_BDEVICE in the HDRC | ||
=== Write Values === | === Write Values === | ||
Revision as of 13:18, 14 August 2013
| 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
Equivalent HDRC port: Possibly MGC_O_HDRC_DEVCTL (0x60)
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)
- Possibly named MGC_M_DEVCTL_SESSION in the HDRC
- Bit 1:
- Unknown. Peripheral routines like this bit.
- Possibly named MGC_M_DEVCTL_HR in the HDRC
- Bit 2:
- Set if calculator is host.
- Possibly named MGC_M_DEVCTL_HM in the HDRC
- Bit 3:
- Reset if VBus is externally powered.
- Possibly named MGC_M_DEVCTL_VBUS in the HDRC
- Bit 4:
- Set if VBus is externally powered.
- Possibly named MGC_M_DEVCTL_VBUS in the HDRC
- Bit 5:
- Always 0
- Possibly named MGC_M_DEVCTL_LSDEV in the HDRC
- Possibly actually indicates whether the bus is in low-speed or full-speed
- Bit 6:
- Set if calculator is successfully hosting a device. It gets set when the device turns on.
- Possibly named MGC_M_DEVCTL_FSDEV in the HDRC
- Possibly actually indicates whether the bus is in low-speed or full-speed
- Bit 7:
- Reset if A-Type cable is currently inserted.
- Possibly named M_DEVCTL_BDEVICE in the HDRC
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.
