mfrc522 NXP Semiconductors, mfrc522 Datasheet - Page 46

• Manufacturer Part Number: mfrc522
• Description: Contactless Reader Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
10. DIGITAL Interfaces
112132
Product data sheet
10.1 Automatic μ-Controller Interface Type Detection
10.2 SPI Compatible interface
The MFRC522 supports direct interfacing of various hosts as the SPI, I
UART interface type. The MFRC522 resets its interface and checks the current host
interface type automatically having performed a Power-On or Hard Reset. The MFRC522
identifies the host interface by the means of the logic levels on the control pins after the
Reset Phase. This is done by a combination of fixed pin connections.The following table
shows the different configurations:
Table 135: Connection Scheme for detecting the different Interface Types
A serial peripheral interface (SPI compatible) is supported to enable high speed
communication to the host. The SPI Interface can handle data speed of up to 10 Mbit/s. In
the communication with a host MFRC522 acts as a slave receiving data from the external
host for register settings and to send and receive data relevant for the communication on
the RF interface.
Remark: Overview on the pin behavior
Pin behavior
MFRC522
SDA
Pin
I²C
EA
D7
D6
D5
D4
D3
D2
D1
Rev. 3.2 — 22 May 2007
DTRQ
UART
Input
MX
RX
TX
0
0
-
-
-
-
Serial Interface Types
Output
MISO
MOSI
NSS
SCK
SPI
0
1
-
-
-
-
Contactless Reader IC
MFRC522
2
© NXP B.V. 2007. All rights reserved.
C and serial
ADR_1
ADR_0
ADR_2
ADR_3
ADR_4
ADR_5
In/Out
SDA
SCL
I
EA
2
1
C
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