SLOU186F
–
AUGUST 2006
–
REVISED AUGUST 2010
Table 5-20. RX Special Setting Register (Address 0Ah)
Sets the gains and filters directly
Register default is set to 0x40 at POR = H or EN = L, and at each write to the ISO control register.
Bit
Bit Name
Function
Comments
B7
C212
Bandpass 110 kHz to 570 kHz
Appropriate for 212-kHz sub-carrier system
B6
C424
Bandpass 200 kHz to 900 kHz
Appropriate for 424-kHz sub-carrier used in ISO15693 and Tag-It
B5
M848
Bandpass 450 kHz to 1.5 MHz
Appropriate for Manchester-coded 848-kHz sub-carrier used in ISO14443A
B4
hbt
Bandpass 100 kHz to 1.5 MHz
Appropriate for highest bit rate (848 kbps) used in high-bit-rate ISO14443
Gain reduced for 7 dB
B3
gd1
01 gain reduction for 5 dB
10 gain reduction for 10 dB
Sets the RX gain reduction
B2
gd2
11 gain reduction for 15 dB
B1
agcr
AGC activation level change
AGC activation level changed from 5 times the digitizing level to 3 times the
digitizing level.
B0
no-lim
AGC action is not limited in time
AGC action can be done any time during receive process. It is not limited to the
start of receive.
Table 5-21. Regulator and I/O Control (0Bh)
Control the three voltage regulators
Register default is set to 0x87 at POR = H or EN = L
Bit
Bit Name
Function
Comments
B7
auto_reg
0 = setting regulator by option bits
Auto system sets VDD_RF to VIN
–
250 mV and VDD_A and VDD_X to VIN
–
(vrs3_5 and vrs2, vrs1 and vrs0)
250 mV, but not higher than 3.4 V.
1 = automatic setting
B6
en_ext_pa
Support for external power
Receiver inputs accept externally demodulated sub-carrier, OOK pin becomes
amplifier
modulation output for external amplifier.
B5
io_low
1 = enable low peripheral
When HIGH, it decreases output resistance of logic outputs. Should be set
communication voltage
HIGH when VDD_I/O voltage is below 2.7 V.
B4
Unused
Default is LOW.
B3
Unused
Default is LOW.
B2
vrs2
Voltage set MSB
vrs3_5 = L: VDD_RF, VDD_A, VDD_X range 2.7 V to 3.4 V
B1
vrs1
B0
vrs0
Voltage set LSB
30
System Description
Copyright
©
2006
–
2010, Texas Instruments Incorporated
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