Difference between revisions of "83Plus:Ports:8F"

From WikiTI
Jump to: navigation, search
(Confirmed that port 8F is DEVCTL)
 
(2 intermediate revisions by 2 users not shown)
Line 1: Line 1:
 
[[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|0F}}
+
{{84P-Only Port|07}}
 
== 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.
+
** Named MGC_M_DEVCTL_SESSION in the HDRC
−
* Bit 2: Set if calculator is host.
+
** Set if VBus is high. (Cutoff between 1.5 V and 3 V)
−
* Bit 3: Reset if VBus is externally powered.
+
* Bit 1:
−
* Bit 4: Set if VBus is externally powered.
+
** Named MGC_M_DEVCTL_HR in the HDRC
−
* Bit 5: Always 0
+
** Peripheral routines like this bit.
−
* 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.
+
** Named MGC_M_DEVCTL_HM in the HDRC
 +
** Set if calculator is host.
 +
* Bit 3:
 +
** Named MGC_M_DEVCTL_VBUS in the HDRC
 +
** Reset if VBus is externally powered.
 +
* Bit 4:
 +
** Named MGC_M_DEVCTL_VBUS in the HDRC
 +
** Set if VBus is externally powered.
 +
* Bit 5:
 +
** Always 0
 +
** 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.
 +
** Named MGC_M_DEVCTL_FSDEV in the HDRC
 +
** Possibly actually indicates whether the bus is in low-speed or full-speed
 +
* Bit 7:
 +
** Named M_DEVCTL_BDEVICE in the HDRC
 +
** Set if we are B-device (i.e. peripheral). This can change if you're implementing USB OTG.
  
 
=== Write Values ===
 
=== Write Values ===
Line 24: Line 44:
  
 
== Comments ==
 
== Comments ==
−
If VBus is internally powered and you short circuit it, it will power down.
+
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.
+

Latest revision as of 18:32, 29 October 2014

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:
    • Named MGC_M_DEVCTL_SESSION in the HDRC
    • Set if VBus is high. (Cutoff between 1.5 V and 3 V)
  • Bit 1:
    • Named MGC_M_DEVCTL_HR in the HDRC
    • Peripheral routines like this bit.
  • Bit 2:
    • Named MGC_M_DEVCTL_HM in the HDRC
    • Set if calculator is host.
  • Bit 3:
    • Named MGC_M_DEVCTL_VBUS in the HDRC
    • Reset if VBus is externally powered.
  • Bit 4:
    • Named MGC_M_DEVCTL_VBUS in the HDRC
    • Set if VBus is externally powered.
  • Bit 5:
    • Always 0
    • 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.
    • Named MGC_M_DEVCTL_FSDEV in the HDRC
    • Possibly actually indicates whether the bus is in low-speed or full-speed
  • Bit 7:
    • Named M_DEVCTL_BDEVICE in the HDRC
    • Set if we are B-device (i.e. peripheral). This can change if you're implementing USB OTG.

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.

Retrieved from "https://wikiti.brandonw.net/index.php?title=83Plus:Ports:8F&oldid=10377"