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AS3953

Datasheet - D e t a il e d D es c r i pt io n

7.8 Transparent Mode

In the Transparent Mode the AS3953 logic is bypassed, AFE input and output signals are directly available on SPI interface pins when /SS signal

is high.



Modulator switch is controlled by pin MOSI (high is modulator on)



Clock extractor output is sent to pin MISO



Demodulator output is sent to pin IRQ

When /SS signal is low the SPI interface pins resume its normal functionality.

In this mode the EEPROM can be accessed via SPI when the RF field is active.

7.9 EEPROM

The AS3953 contains an EEPROM block which can be accessed from both RFID and SPI interface. EEPROM contains 1024 bits (128 bytes)

organized in 32 words of 32 bits. Words in EEPROM are number from 0 to 31(1F[hex]). Bits in a word are numbered from 0 to 31.

Most of the EEPROM is used to store user data (27 words – 864 bits), five words are used to store some housekeeping information (part of the

AS3953 UID, configuration bits which define the AS3953 operating options, lock bits, which control the possibility to write EEPROM words).

Access properties:

RO: Read only, writing to this word is not possible

RW: Reading and writing to this word is possible, writing is disabled once the lock bit is set

OTP: One time programmable. A bit of this word once set to ‘1’ cannot be set back to ‘0’.

7.9.1 UID Word

The UID word contains four LSB bytes of 7 byte UID which is used during anti-collision and selection process. Every IC is programmed by a

unique number during fabrication process at

ams. For details on UID, please refer to Coding of UID on page 12.

7.9.2 Fabrication Data Word

This word stores some IC manufacturer data which is programmed and locked during fabrication process at

ams.

Table 4. EEPROM Organization

Word Address [hex]

Content

Access Properties

0UID

RO

1

Fabrication Data

RO

2

Configuration Word

RW

3

Write Lock Word

OTP

4

Read Lock Word

OTP

5

:

:

:

:

:

:

1F

User Data

RW