ZHCS363L August 2011 – March 2017 TRF7970A
PRODUCTION DATA.
Table 6-37 describes the RX Special Setting register.
Function: Sets the gains and filters directly | |||
Default: 0x40 at POR = H or EN = L, and at each write to the ISO Control register 0x01. When bits B7, B6, B5 and B4 are all zero, the filters are set for ISO/IEC 14443 B (240 kHz to 1.4 MHz). | |||
Bit | Name | Function | Description |
B7 | C212 | Band-pass 110 kHz to 570 kHz | Appropriate for 212-kHz subcarrier system (FeliCa) |
B6 | C424 | Band-pass 200 kHz to 900 kHz | Appropriate for 424-kHz subcarrier used in ISO/IEC 15693 |
B5 | M848 | Band-pass 450 kHz to 1.5 MHz | Appropriate for Manchester-coded 848-kHz subcarrier used in ISO/IEC 14443 A and B |
B4 | hbt | Band-pass 100 kHz to 1.5 MHz Gain reduced for 18 dB |
Appropriate for highest bit rate (848 kbps) used in high-bit-rate ISO/IEC 14443 |
B3 | gd1 | 00 = Gain reduction 0 dB 01 = Gain reduction for 5 dB 10 = Gain reduction for 10 dB 11 = Gain reduction for 15 dB |
Sets the RX gain reduction and reduces sensitivity |
B2 | gd2 | ||
B1 | Reserved | ||
B0 | Reserved |
NOTE
The setting of bits B4, B5, B6 and B7 to 0 selects bandpass characteristic of 240 kHz to 1.4 MHz. This is appropriate for ISO/IEC 14443 B, FeliCa protocol, and ISO/IEC 14443 A higher bit rates of 212 kbps and 424 kbps.