Datasheet

PN512 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2016. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 5.2 — 16 June 2016
111352 88 of 137
NXP Semiconductors
PN512
Full NFC Forum-compliant frontend
11.5 Serial data switch
Two main blocks are implemented in the PN512. The digital block comprises the state
machines, encoder/decoder logic. The analog block comprises the modulator and
antenna drivers, the receiver and amplifiers. The interface between these two blocks can
be configured in the way, that the interfacing signals may be routed to the pins SIGIN and
SIGOUT. SIGIN is capable of processing digital NFC signals on transfer speeds above
424 kbit. The SIGOUT pin can provide a digital signal that can be used with an additional
external circuit to generate transfer speeds above 424 kbit (including 106, 212 and
424 kbit). Furthermore SIGOUT and SIGIN can be used to enable the S
2
C interface in the
card SAM mode to emulate a card functionality with the PN512 and a secure IC. A secure
IC can be the SmartMX smart card controller IC.
This topology allows the analog block of the PN512 to be connected to the digital block of
another device.
The serial signal switch is controlled by the TxSelReg and RxSelReg registers.
Figure 29
shows the serial data switch for TX1 and TX2.
11.6 S
2
C interface support
The S
2
C provides the possibility to directly connect a secure IC to the PN512 in order act
as a contactless smart card IC via the PN512. The interfacing signals can be routed to the
pins SIGIN and SIGOUT. SIGIN can receive either a digital FeliCa or digitized
ISO/IEC 14443A signal sent by the secure IC. The SIGOUT pin can provide a digital
signal and a clock to communicate to the secure IC. A secure IC can be the smart card IC
provided by NXP Semiconductors.
The PN512 has an extra supply pin (SVDD and PVSS as Ground line) for the SIGIN and
SIGOUT pads.
Figure 31
outlines possible ways of communications via the PN512 to the secure IC.
Fig 29. Serial data switch for TX1 and TX2
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INTERNAL
CODER
INVERT IF
InvMod = 1
DriverSel[1:0]
00
01
10
11
3-state
to driver TX1 and TX2
0 = impedance = modulated
1 = impedance = CW
1
INVERT IF
PolMFin = 0
MFIN
envelope