NXP Semiconductors PN7462 series User Manual page 148

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present when the device is within the RF-Field. PLL clock is available as soon as the
CLIF PLL is enabled and locked to the input clock.
The HFO (high frequency oscillator – 20 MHz nominal) clock is always available as soon
systems is active. Some functional blocks use this clock as the functionality must be
available even if the main contactless clock is not available. Modules interfacing the
ARM sub-system (APB register interface and Buffer Manager) also operate at system
clock (nominal 20 MHz).
12.4.2 Digital PLL (DPLL) Control
For Active Load Modulation (ALM) with a single loop antenna the PLL is extended by a
digital PLL (DPLL), which is controlled by this module. For ALM with a single loop
antenna the generated frequency by the PLL must be aligned with the field clock in
phase and frequency. During transmission, the frequency is kept constant (as close as
possible to the frequency of the reader) such that the phase drift between the RF signal
generated by the reader and the transmitted signal by the card (ALM) is kept to a
minimum.
12.4.3 CLIF Signal Processing (SigPro) Block
This SigPro module performs digital signal processing. The input is the demodulated
envelope signal and the output is a digital data signal, which is further processed in the
Rx-Decoder. The SigPro module consists of three modes i.e., reader-mode, card-mode,
and ADC based card-mode. The SigPro is the interface between the analog frontend and
the Rx-Decoder. The SigPro generates a bit stream out of the input signal (analog
demodulator signal or ADC data signal). The output data is further processed in the Rx-
Decoder for protocol handling.
12.4.3.1 Functional features
• Decode card-mode ISO14443 Type A (106 kBd, 212 kBd, 424 kBd, 848 kBd): Miller
• Decode card-mode ISO14443 Type B (106 kBd, 212 kBd, 424 kBd, 848 kBd): NRZ
• Decode card-mode ISO18092 (106kBd): A: Miller decoder (100 % ASK modulation)
• Decode card-mode ISO18092 (212kBd, 424kBd: Felica): Manchester decoder (10 %
• Target mode detection (Type A / Type B / FeliCa)
• Decode reader-mode ISO14443 Type A (106 kBd): Manchester decoder (848kHz
• Decode reader-mode ISO14443 Type A (212 kBd, 424 kBd, 848 kBd): BPSK
• Decode reader-mode ISO14443 Type B BPSK decoder (848 kHz subcarrier with
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decoder (100 % ASK modulation)
decoder (10 % ASK modulation)
ASK Modulation)
subcarrier with load modulation)
decoder (848 kHz subcarrier with load modulation)
load modulation).
All information provided in this document is subject to legal disclaimers.
Rev. 1.4 — 14 May 2018
314514
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PN7462 family HW user manual
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