It uses a synchronous communication protocol with only 2 channels (there is a third, but it is coupled to reference or GND), in fact it is also known as TWI (Two Wire Interface):
ມັນໃຊ້ອະນຸສັນຍາການສື່ສານແບບປະສານງານທີ່ມີພຽງແຕ່ 2 ຊ່ອງທາງ (ມີຊ່ອງທາງທີສາມ, ແຕ່ມັນຖືກບວກກັບການອ້າງອີງຫຼື GND), ໃນຄວາມເປັນຈິງມັນຍັງຖືກເອີ້ນວ່າ TWI (Two Wire Interface):