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Programmable I/O Port: Difference between revisions

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(in/out port)
(only top 2 bits of RDIO used)
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There is the register commonly referred to as '''WRIO''' for short located at 4201h.  It has [http://www.learningaboutelectronics.com/Articles/Open-collector-output.php open collector output].<sup>[2]</sup>  WRIO is the out-port.
There is the register commonly referred to as '''WRIO''' for short located at 4201h.  It has [http://www.learningaboutelectronics.com/Articles/Open-collector-output.php open collector output].<sup>[2]</sup>  WRIO is the out-port.


There is also the RDIO register at 4213h.  RDIO is the in-port.
There is also the RDIO register at 4213h.  Only the top two bits are used by the [[control deck]].  RDIO is the in-port.


=== See Also ===
=== See Also ===

Revision as of 03:53, 20 December 2023

The 8-bit Programmable I/O Port allows the 5A22 to communicate with SNES peripherals.

There is the register commonly referred to as WRIO for short located at 4201h. It has open collector output.[2] WRIO is the out-port.

There is also the RDIO register at 4213h. Only the top two bits are used by the control deck. RDIO is the in-port.

See Also

References

  1. Official Super Nintendo development manual on the programmable i/o port: Page 2-14-1 of Book I
  2. https://problemkaputt.de/fullsnes.htm#snescontrollersioportsmanualreading
  3. page 2-28-1 of Book I on WRIO
  4. page 2-28-7 of Book I on RDIO