MFRC52201HN1/TRAYB NXP [NXP Semiconductors], MFRC52201HN1/TRAYB Datasheet - Page 22

• Manufacturer Part Number: MFRC52201HN1/TRAYB
• Description: Contactless reader IC
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
MFRC522_33
Product data sheet
PUBLIC
8.1.4.11 Switching between F/S mode and HS mode
8.1.4.12 MFRC522 at lower speed modes
After reset and initialization, the MFRC522 is in Fast mode (which is in effect F/S mode as
Fast mode is downward-compatible with Standard mode). The connected MFRC522
recognizes the “S 00001XXX A” sequence and switches its internal circuitry from the Fast
mode setting to the HS mode setting.
The following actions are taken:
It is possible for system configurations that do not have other I
the communication to switch to HS mode permanently. This is implemented by setting
Status2Reg register’s I
is not required to be sent. This is not defined in the specification and must only be used
when no other devices are connected on the bus. In addition, spikes on the I
must be avoided because of the reduced spike suppression.
MFRC522 is fully downward-compatible and can be connected to an F/S mode I
system. The device stays in F/S mode and communicates at F/S mode speeds because a
master code is not transmitted in this configuration.
1. Adapt the SDA and SCL input filters according to the spike suppression requirement
2. Adapt the slope control of the SDA output stages.
in HS mode.
Rev. 3 — 26 October 2009
2
CForceHS bit to logic 1. In permanent HS mode, the master code
112133
2
C-bus devices involved in
Contactless reader IC
MFRC522
© NXP B.V. 2009. All rights reserved.
2
C-bus lines
2
C-bus
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