AN3985 Datasheet, PDF (60/105 Pages) STMicroelectronics – Using the CR95HF library with STM8L microcontrollers

LRIxK layer
6
LRIxK layer
AN3985
6.1
Overview
LRIxK devices are compliant with ISO/IEC 15693 specifications. Several functions of the
LRIxK-R layer are identical to ISO/IEC 15693 functions.
This layer includes all the commands defined in the LRIxK datasheets.
The LRIX layer applied to LRI1k, LRIS2k and LRI2k and is composed of:
● LRIxK_command.c
● LRIxK_command.h
6.2
6.2.1
6.2.2
Command format
CRC16 management
The LRIxK datasheet defines a two bytes CRC. It is appended to the RF command in order
to check the data transmission between CR95HF and a contactless tag.
Bit 0 of parameter (AppendCRC) of ProtocolSelect command is set in the ProtocolSelect
function. Thus the CR95HF manages the CRC of the RF command.
Request flag management
The request flag is detailed in Chapter 5.3.2: Request flag management.
The request flag byte is managed by the user application. Each bit or flag specifies the
actions to be performed by the contactless tag and whether the corresponding fields are
present or not. Bit 3 (Inventory_flag) of the request flag defines the contents of the 4 MSBs
(bits 5 to 8). When bit 3 is reset (0), bits 5 to 8 define the contactless tag selection criteria.
When bit 3 is set (1), bits 5 to 8 define the contactless tag Inventory parameters.
Some commands of LRIxK datasheet required specific request flags. Those Request flags
are forced inside the LRIxK layer function.
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Doc ID 022255 Rev 2