ST25TV512 datasheet(77/90 Pages) STMICROELECTRONICS

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Appendix A Bit representation and coding for fast commands

Data bits are encoded using Manchester coding, according to the following schemes. For the low data rate, same

subcarrier frequency or frequencies is/are used. In this case, the number of pulses is multiplied by 4 and all times

increase by this factor. For the fast commands using one subcarrier, all pulse numbers and times are divided by

two.

A.1

Bit coding using one subcarrier

A.1.1

High data rate

For the fast commands, a logic 0 starts with four pulses at 423.75 kHz (fC / 32) followed by an unmodulated time

of 9.44 µs, as shown in Figure 32.

Figure 32. Logic 0, high data rate, fast commands

18.88 µs

For the fast commands, a logic 1 starts with an unmodulated time of 9.44 µs followed by four pulses of 423.75

kHz (fC / 32), as shown in Figure 33 .

Figure 33. Logic 1, high data rate, fast commands

18.88 µs

A.1.2

Low data rate

For the fast commands, a logic 0 starts with 16 pulses at 423.75 kHz (fC / 32) followed by an unmodulated time of

37.76 µs, as shown in Figure 34.

Figure 34. Logic 0, low data rate, fast commands

75.52 µs

For the fast commands, a logic 1 starts with an unmodulated time of 37.76 µs followed by 16 pulses at 423.75

kHz (fC / 32), as shown in Figure 35.

Figure 35. Logic 1, low data rate, fast commands

75.52 µs

Note:

For fast commands, bit coding using two subcarriers is not supported.

ST25TV02K ST25TV512

Bit representation and coding for fast commands

DS12074 - Rev 11

page 77/90

ST25TV512 Scheda tecnica(PDF) 77 Page - STMicroelectronics