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 61 of 120
NXP Semiconductors
MFRC631
High performance ISO/IEC 14443 A/B reader solution
Table 48. WaterLevel bits
Bit Symbol Description
7 to 0 WaterLevel Sets a level to indicate a FIFO-buffer state which can be read from bits
HighAlert and LowAlert in the FifoControl. In 512-byte FIFO mode, the
register is extended by bit WaterLevel in the FIFOControl. This
functionality can be used to avoid a FIFO buffer overflow or underflow:
The bit HiAlert bit in FIFO Control is read logic 1, if the number of bytes
in the FIFO-buffer is equal or less than the number defined by
WaterLevel.
The bit LoAlert bit in FIFO control is read logic 1, if the number of bytes
in the FIFO buffer is equal or less than the number defined by
WaterLevel.
Note: For the calculation of HiAlert and LoAlert see register description
of these bits (Section 9.4.1 “
FIFOControl”).