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Programmable I/O Port: Difference between revisions
From SnesLab
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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
- Official Super Nintendo development manual on the programmable i/o port: Page 2-14-1 of Book I
- https://problemkaputt.de/fullsnes.htm#snescontrollersioportsmanualreading
- page 2-28-1 of Book I on WRIO
- page 2-28-7 of Book I on RDIO