mfrc52301hn1-trayb NXP Semiconductors, mfrc52301hn1-trayb Datasheet - Page 23

• Manufacturer Part Number: mfrc52301hn1-trayb
• Description: Contactless Reader Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
MFRC523_33
Product data sheet
PUBLIC
8.3.4.12 MFRC523 at lower speed modes
8.3.4.11 Switching between F/S mode and HS mode
After reset and initialization, the MFRC523 is in Fast mode (which is in effect F/S mode as
Fast mode is downward-compatible with Standard mode). The connected MFRC523
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.
MFRC523 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.
All information provided in this document is subject to legal disclaimers.
2
Rev. 3.3 — 5 March 2010
CForceHS bit to logic 1. In permanent HS mode, the master code
115233
2
C-bus devices involved in
Contactless reader IC
MFRC523
© NXP B.V. 2010. All rights reserved.
2
C-bus lines
2
C-bus
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