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 100 of 137
NXP Semiconductors
PN512
Full NFC Forum-compliant frontend
18. PN512 command set
The PN512 operation is determined by a state machine capable of performing a set of
commands. A command is executed by writing a command code (see Table 158
) to the
CommandReg register.
Arguments and/or data necessary to process a command are exchanged via the FIFO
buffer.
18.1 General description
The PN512 operation is determined by a state machine capable of performing a set of
commands. A command is executed by writing a command code (see Table 158
) to the
CommandReg register.
Arguments and/or data necessary to process a command are exchanged via the FIFO
buffer.
18.2 General behavior
•
Each command that needs a data bit stream (or data byte stream) as an input
immediately processes any data in the FIFO buffer. An exception to this rule is the
Transceive command. Using this command, transmission is started with the
BitFramingReg register’s StartSend bit.
• Each command that needs a certain number of arguments, starts processing only
when it has received the correct number of arguments from the FIFO buffer.
• The FIFO buffer is not automatically cleared when commands start. This makes it
possible to write command arguments and/or the data bytes to the FIFO buffer and
then start the command.
• Each command can be interrupted by the host writing a new command code to the
CommandReg register, for example, the Idle command.
Fig 36. Oscillator start-up time
001aak596
t
startup
t
d
t
osc
t
device activation
oscillator
clock stable
clock ready