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 38 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.1.8.9 Baud rates using Timer2 (Debug UART mode 1 and 3)
Timer2 has a programming mode to function as baud rate generator for the Debug UART.
In this mode the baud rate is given by formula:
Baud rate using Timer2
(7)
When rewriting this formula, the value for the Timer2 reload values T2RCH/L is calculated
from the desired baud rate as follows:
Reload value T2RCH/L
(8)
For details on programming Timer2 to function as baud rate generator for the Debug
UART (see Section 8.1.7 “
Timer2 description” on page 27).
Note: the frequency f
clk
is the internal microcontroller frequency. If there is no clock divider
then f
clk
= f
osc
.
The next table lists the maximum baud rates when using Timer2.
8.2 General purpose IOs configurations
This chapter describes the different configurations for the IO pads:
P72, alternate function SCK
P71, alternate function MISO
P70_IRQ
P35
P34, alternate function SIC_CLK
P33_INT1
P32_INT0
P31, alternate function UART_TX
P30, alternate function UART_RX
Note that in Hard Power Down mode, these ports are disconnected from their supply rail.
For a given port x, there are three configuration registers:
PxCFGA[n]
PxCFGB[n]
Px[n]
Table 58. Maximum baud rates using Timer2
Reload value T2RCH/L f
CLK
divided by Baud rate Unit
6.78 13.56 27.12 MHz
FFFF 16 424 847.5 1695 kb/s
f
clk
16 65536 T2RCH T2RCL(,)– 
----------------------------------------------------------------------------------
65536
f
clk
16 Baudrate
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