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 35 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.1.8.4 S0BUF register
This register is implemented twice. Writing to S0BUF writes to the transmit buffer. Reading
from S0BUF reads from the receive buffer. Only hardware can read from the transmit
buffer and write to the receive buffer.
8.1.8.5 Mode 0 baud rate
In mode 0, the baud rate is derived from the CPU states signals and thus:
Baud rate in mode 0
(1)
The next table lists the baud rates in Debug UART mode 0.
8.1.8.6 Mode 2 baud rate
In mode 2, the baud rate depends on the value of bit SMOD from the SFR register PCON.
Baud Rate using mode 2
(2)
The next table lists the baud rates in Debug UART mode 2.
Table 51. Debug UART S0BUF Register (SFR: address 99h) bit allocation
Bit 7 6 5 4 3 2 1 0
Symbol S0BUF[7:0]
Reset 00000000
Access R/W R/W R/W R/W R/W R/W R/W R/W
Table 52. Description of S0BUF bits
Bit Symbol Description
7 to 0 S0BUF[7:0] Writing to S0BUF writes to the transmit buffer.
Reading from S0BUF reads from the receive buffer.
Table 53. Baud rates in mode 0
Conditions Min Typ Max Unit
f
CLK
6.78 13.56 27.12 MHz
Baud rate 1.13 2.26 4.52 Mb/s
clk
6
-------
Table 54. Baud rates in mode 2
Conditions Min Typ Max Unit
f
CLK
6.78 13.56 27.12 MHz
Baud rate (SMOD=0) 212 424 847.5 kb/s
Baud rate (SMOD=1) 424 847.5 1695 kb/s
2
SMOD
32
----------------
f
clk
