AS3955 datasheet(40/111 Pages) AMSCO

40 / 111 page

Page 40

ams Datasheet

Document Feedback

[v1-01] 2015-Apr-29

AS3955 − Detailed Description

The voltage level of the supply on VP_IO is measured when tag

enters RF field. The selected voltage level threshold can be

properly measured only if the RF field is strong enough to

provide sufficient supply voltage level. When small antennas

are used, it is advisable to set lower threshold.

Bit arbit_mod defines arbitration mode during mutual EEPROM

access via SPI / I²C and RF side. If arbit_mod is set to 0, then the

EEPROM access follows the first-come-first-serve principle. If

arbit_mod is set to 1, then the RF part will always have higher

priority over SPI / I²C. For further details, please refer to section

Interface Arbitration.

The i2c_addr bits represent lower three bits of the I²C address.

The upper four bits of the I²C address that represent a group

shall be set to 1010b.

Configuration Byte IC_CFG1

Figure 45:

Configuration Byte IC_CFG1

Note(s) and/or Footnote(s):

1. This byte can always be accessed for read and write via SPI / I²C and can be accessed for read and write from the RF side if rfcfg_en

is set to 1.

If bit en_rx_crc is set to 1 then the CRC shall be part of the

message in the buffer. This implies that maximum message

effective length is reduced to 30 bytes. CRC check is performed

regardless of the value of the en_rx_crc bit.

Conf. Bit

Name

Default

Function

Note

en_rx_crc

1: CRC stored in the buffer in the tunneling mode

vreg<4>

Voltage level for voltage regulator VP_REG

(see Figure 16)

vreg<3>

vreg<2>

vreg<1>

vreg<0>

rreg<1>

Output resistance value for voltage regulator VP_REG

(see Figure 15)

rreg<0>

AS3955 データシート(PDF) 40 Page - ams AG

AS3955 データシート(HTML) 40 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

データシートダウンロード