Figure 475. S1 Signal Coding; Figure 476. S2 Signal Coding - ST STM32L4 5 Series Reference Manual

RM0351
44 Single Wire Protocol Master Interface (SWPMI)
44.1 Introduction
The Single Wire Protocol Master Interface (SWPMI) is the master interface corresponding to
the Contactless front-end (CLF) defined in the ETSI TS 102 613 technical specification.
The principle of the Single wire protocol (SWP) is based on the transmission of digital
information in full duplex mode:
•
S1 signal (from Master to Slave) is transmitted by a digital modulation (L or H) in the
voltage domain (refer to
•
S2 signal (from Slave to Master) is transmitted by a digital modulation (L or H) in the
current domain (refer to
Single Wire Protocol Master Interface (SWPMI)
Figure 475: S1 signal
Figure 476: S2 signal

Figure 475. S1 signal coding

Figure 476. S2 signal coding

DocID024597 Rev 5
coding),
coding).
1491/1830
1517