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 40 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.2.1 Pad configurations description
8.2.1.1 Open-drain
In open drain configuration, an external pull-up resistor is required to output or read a
logic 1. When writing polarity Px[n] to logic 0, the GPIO pad is pulled down to logic 0.
When writing polarity Px[n] to logic 1 the GPIO pad is in High Impedance.
Fig 6. Open-drain
CPU_CLK
en_n
zi
output mode
input mode
Write Px[n]
en_n
zi
GPIO pad
Read Px[n]
GPIO pad
CPU_CLK
1
2
Px[n]
zi
e_hd
e_pu
e_p
en_n
GND
DVDD
GND
xVDD
3
Control
PxCFGA[n] = “0”
PxCFGB[n] = “0”
“0”
GPIO pad
CPU_CLK