Difference between revisions of "83Plus:Ports:4C"
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Thepenguin77 (Talk | contribs) (Created page with '4C - USB Controller Status USB Controller Status {{84P-Only Port|0C}} == Synopsis == '''Port Number:''' 4Ch…') |
Thepenguin77 (Talk | contribs) |
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[[Category:83Plus:Ports:By Address|4C - USB Controller Status]] [[Category:83Plus:Ports:By Name|USB Controller Status]] | [[Category:83Plus:Ports:By Address|4C - USB Controller Status]] [[Category:83Plus:Ports:By Name|USB Controller Status]] | ||
| − | {{84P-Only Port| | + | {{84P-Only Port|04}} |
== Synopsis == | == Synopsis == | ||
'''Port Number:''' 4Ch | '''Port Number:''' 4Ch | ||
Revision as of 20:01, 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 04. On the TI-83 Plus Silver Edition, this port has no effect. |
Synopsis
Port Number: 4Ch
Function: USB Controller Status
This port seems to be a status port for the USB controller. It is closely tied with port 54. If the USB controller is not powered, this port will always read either 22h or 2Ah depending on what was last written to bit 3.
Read Values
- Bit 0: Always 0
- Bit 1: Always 1
- Bit 2: Always 0
- Bit 3: This bit is only significant if 2, port 54 is set. If set, the 80-AF ports are active. Causes a 0.19 mA increase in draw.
- Bit 4: Reflection of 2, port 54.
- Bit 5: Inverse of 6, port 54.
- Bit 6: Reflection of 7, port 54.
- Bit 7: Always 0
Write Values
- Bits 0-2: No effect
- Bit 3: If 2, port 54 is also set. This enables the 80-AF ports. Causes a 0.19 mA increase in draw.
- Bit 4-7: Not used
Comments
USB initialization should only be attempted if this port reads 5Ah or 1Ah. In reality though, 1Ah is only used if 3, port 3A is set, so 5Ah is the value you are looking for.
