Datasheet

PN532_C1 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.6 — 28 November 2017
115436 73 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.3.4 HIGH SPEED UART (HSU)
The High Speed UART (HSU) provides a high speed link to the host (up to 1.288 Mbit/s).
The HSU is a full duplex serial port. The serial port has a Receive-buffer: in conjunction
with the FIFO manager, the reception of several bytes can be performed without strong
CPU real time constraints. However, if the Receive FIFO still has not been read by the
CPU, and the number of receive bytes is greater than the Receive FIFO size then the new
incoming bytes will be lost.
The HSU receive and transmit data registers are both accessed by firmware in the FIFO
manager FDATA register. Writing to FDATA loads the transmit register, reading from
FDATA accesses the separate receive register.
The characteristics of the UART are the following:
• Full duplex serial port
• Receive buffer to allow reception of byte while the previous bytes are stored into the
FIFO manager
• 8-bit data transfers
• Programmable baud rate generator using prescaler for transmission and reception
• Based on 27.12 MHz clock frequency
• Dedicated protocol preamble filter
• Wake-up generator