MFRC52201HN1/TRAYB NXP [NXP Semiconductors], MFRC52201HN1/TRAYB Datasheet - Page 20

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

NXP Semiconductors
MFRC522_33
Product data sheet
PUBLIC
8.1.4.10 Serial data transfer format in HS mode
8.1.4.8 High-speed mode
8.1.4.9 High-speed transfer
In High-speed mode (HS mode), the device can transfer information at data rates of up to
3.4 Mbit/s, while remaining fully downward-compatible with Fast or Standard mode
(F/S mode) for bidirectional communication in a mixed-speed bus system.
To achieve data rates of up to 3.4 Mbit/s the following improvements have been made to
I
The HS mode serial data transfer format meets the Standard mode I
HS mode can only start after all of the following conditions (all of which are in F/S mode):
When HS mode starts, the active master sends a repeated START condition (Sr) followed
by a 7-bit slave address with a R/W bit address and receives an acknowledge bit (A) from
the selected MFRC522.
Data transfer continues in HS mode after the next repeated START (Sr), only switching
back to F/S mode after a STOP condition (P). To reduce the overhead of the master code,
a master links a number of HS mode transfers, separated by repeated START conditions
(Sr).
2
1. START condition (S)
2. 8-bit master code (00001XXXb)
3. Not-acknowledge bit (A)
Fig 18. I
C-bus operation.
•
•
S
The inputs of the device in HS mode incorporate spike suppression, a Schmitt trigger
on the SDA and SCL inputs and different timing constants when compared to
F/S mode
The output buffers of the device in HS mode incorporate slope control of the falling
edges of the SDA and SCL signals with different fall times compared to F/S mode
MASTER CODE
F/S mode
2
C-bus HS mode protocol switch
A
Rev. 3 — 26 October 2009
Sr SLAVE ADDRESS
112133
HS mode (current-source for SCL HIGH enabled)
R/W
A
(n-bytes + A)
DATA
A/A
Contactless reader IC
2
MFRC522
C-bus specification.
Sr
P
HS mode continues
© NXP B.V. 2009. All rights reserved.
SLAVE ADDRESS
F/S mode
001aak749
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