AN3057

RF - I²C arbitration mechanism description

Doc ID 16239 Rev 4

7/15

Commands in the RF read command group are:

●

Read Block, Fast Read Single Block, Read Multiple Blocks, Fast Read Multiple Blocks

●

Get System Info

●

Select

●

Reset to Ready

●

Get Multiple Block Security Status

●

Initiate, Fast Initiate

●

Inventory Initiated

Write command group

When decoding an RF write command, the M24LRxx is in the RF busy state from the SOF

(start of frame) of the request frame until the EOF (end of frame) of the response frame.

commands in the write group.

Figure 5.

RF write command busy state

Commands in the RF write command group are:

●

Write Block

●

Write AFI, Lock AFI

●

Write DSFID, Lock DSFID

●

Write-sector Password, Lock-sector Password, Present-sector Password

Stay Quiet command

The Stay Quiet command is the only command defined as a single request frame (not

followed by a response frame). The M24LRxx is in the RF busy state during the whole [SOF

…. EOF] sequence as shown in the figure below.

Figure 6.

RF Stay Quiet command busy state

Inventory command

An Inventory command is used when several M24LRxx devices are inside the range of the

same RF electromagnetic field.

When the Inventory command scans 16 slots, the M24LRxx is in the RF busy state from the

SOF (start of frame) of the request frame until the EOF (end of frame) of the response

frame.

Note:

The addressed M24LRxx device might stay a long time in the RF busy state if it is decoded

SOF

Request

EOF

RF busy

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Response

SOF

EOF

SOF

Request

EOF

RF busy

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