Product data

MFRC631 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.3 — 4 February 2014
227433 16 of 120
NXP Semiconductors
MFRC631
High performance ISO/IEC 14443 A/B reader solution
Remark: To send more bytes in one data stream the NSS signal must be LOW during the
send process. To send more than one data stream the NSS signal must be HIGH between
each data stream.
8.4.3 RS232 interface
8.4.3.1 Selection of the transfer speeds
The internal UART interface is compatible to a RS232 serial interface.
Table 13 “
Selectable transfer speeds” describes examples for different transfer speeds
and relevant register settings. The resulting transfer speed error is less than 1.5 % for all
described transfer speeds. The default transfer speed is 115.2 kbit/s.
To change the transfer speed, the host controller has to write a value for the new transfer
speed to the register SerialSpeedReg. The bits BR_T0 and BR_T1 define factors to set
the transfer speed in the SerialSpeedReg.
Table 12 “
Settings of BR_T0 and BR_T1” describes the settings of BR_T0 and BR_T1.
Table 11. Timing conditions SPI
Symbol Parameter Min Typ Max Unit
t
SCKL
SCK LOW time 50 - - ns
t
SCKH
SCK HIGH time 50 - - ns
t
h(SCKH-D)
SCK HIGH to data input hold time 25 - - ns
t
su(D-SCKH)
data input to SCK HIGH set-up time 25 - - ns
t
h(SCKL-Q)
SCK LOW to data output hold time - - 25 ns
t
(SCKL-NSSH)
SCK LOW to NSS HIGH time 0 - - ns
t
NSSH
NSS HIGH time 50 - - ns
Fig 10. Connection to host with SPI
001aaj641
t
SCKL
t
NSSH
t
SCKH
t
SCKL
t
h(SCKL-Q)
t
su(D-SCKH)
t
h(SCKH-D)
t
h(SCKL-Q)
t
(SCKL-NSSH)
SCK
MOSI
MISO
MSB
MSB
LSB
LSB
NSS