Today we are releasing a new resolution to replace the problematic Master/Slave SPI terminology. We are recommending using the terms PICO (Peripheral In, Controller Out) and POCI (Peripheral Out, Controller In). You can view our original blog post on reasoning to move away from the Master/Slave terminology here. This change is the result of research done by OSHWA and guided by industry leaders and stakeholders to change the resolution to use PICO/POCI going forward.  You can read the new resolution here.

This is an important update to replace an earlier resolution with terms C*PO and COPI as a move away from MOSI/MISO.  After publishing the resolution containing C*PO and COPI, it was brought to OSHWA’s attention that one of those acronyms is an offensive term in Polish. Our initial review of the options did not identify this problem.  Therefore, we are moving to update the terms to PICO and POCI.  We conducted a broader language review and included more industry leaders and community stakeholders when considering PICO/POCI.

What we did and how we did it:

After being alerted to problems with MOSI/MISO, the OSHWA board consulted with various stakeholders and industry leaders.  Those discussions made it clear that we needed to choose a better term. We took six months to gather advice from industry leaders, community members, and other stakeholders and another six months to investigate the terms PICO and POCI. This included:

  • Checking the terms separately and together
  • Testing the terms in the word safety database, which checks 19 languages with phonetic matching
  • Testing the terms in Google Translate, which provides AI-assisted translations in 108 languages that cover 3.8 billion speakers 
  • Testing potential concerns in Bengali, Bulgarian, Chilean Spanish, Japanese, Mandarin, and Portuguese with native speakers or translators, all of whom confirmed there were no problematic concerns.

While these efforts can never be complete, we believe they have been sufficiently vigorous to give us confidence that PICO and POCI are viable for the future. 

Once the review was complete, the OSHWA board took all the research into consideration and determined PICO/POCI was the recommended path forward.  OSHWA drafted the resolution and circulated it to the initial endorsees for endorsement.  

We invite you to review and endorse the resolution. To endorse the new SPI Resolution, please email with “I endorse the Resolution to Redefine SPI Signal Names”