
CLRC632_35
NXP B.V. 2009. All rights reserved.
Product data sheet
PUBLIC
Rev. 3.5 — 10 November 2009
073935
66 of 126
NXP Semiconductors
CLRC632
Multiple protocol contactless reader IC (MIFARE/I-CODE1)
10.5.4.5
RxThreshold register
Selects thresholds for the bit decoder.
10.5.4.6
BPSKDemControl
Controls BPSK demodulation.
Table 91.
RxThreshold register (address: 1Ch) reset value: 1111 1111b, FFh bit allocation
Bit
7
6
5
4
3
2
1
0
Symbol
MinLevel[3:0]
CollLevel[3:0]
Access
R/W
Table 92.
RxThreshold register bit descriptions
Bit
Symbol
Description
7 to 4
MinLevel[3:0]
the minimum signal strength the decoder will accept. If the signal
strength is below this level, it is not evaluated.
3 to 0
CollLevel[3:0]
the minimum signal strength the decoder input that must be reached
by the weaker half-bit of the Manchester encoded signal to generate
a bit-collision (relative to the amplitude of the stronger half-bit)
Table 93.
BPSKDemControl register (address: 1Dh) reset value: 0001 1110b, 1Eh bit
allocation
Bit
7
6
5
4
3
2
1
0
Symbol
NoRxSOF
NoRxEGT NoRxEOF FilterAmpDet
TauD[1:0]
TauB[1:0]
Access
R/W
Table 94.
BPSKDemControl register bit descriptions
Bit
Symbol
Value
Description
7
NoRxSOF
1
a missing SOF in the received data stream is ignored and no
framing errors are indicated
0
a missing SOF in the received data stream generates framing
errors
6
NoRxEGT
1
an EGT which is too short or too long in the received data stream
is ignored and no framing errors are indicated
0
an EGT which is too short or too long in the received data stream
will cause framing errors
5
NoRxEOF
1
a missing EOF in the received data stream is ignored and no
framing errors indicated
0
a missing EOF in the receiving data stream produces framing
errors
4
FilterAmpDet -
switches on a high-pass lter for amplitude detection
3 to 2
TauD[1:0]
-
changes the time constant of the internal PLL whilst receiving
data
1 to 0
TauB[1:0]
-
changes the time constant of the internal PLL during data bursts