RF - I²C arbitration mechanism description

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Doc ID 16239 Rev 4

2.2

Communication arbitration when the RF and I²C channels are

both active

Arbitration depends on whether the I²C and RF channels are in the busy state. Section 2.2.1

and Section 2.2.2 give the definitions of the I²C and RF busy states, respectively.

2.2.1

I²C busy states

When decoding an I²C read command, the M24LRxx is in the I²C busy state from the Start

condition until the Stop condition.

Figure 2.

I²C read command busy state

When decoding an I²C write command, the M24LRxx is in the I²C busy state from the Start

condition until the completion of the write cycle (triggered by the Stop condition).

Figure 3.

I²C write command busy state

2.2.2

RF busy states

In most cases, an RF command is defined as a received request initiated by the SOF (start

of frame) and terminated by the decoding of the EOF (end of frame) of the response frame.

RF commands can be gathered into several groups:

Read command group

When decoding an RF read 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. The

figure below shows the RF busy state of commands in the read group.

Figure 4.

RF read command busy state

Start

Read command

Stop

I²C busy

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Start

Write command

Stop

I²C busy

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Write cycle

SOF

Request

EOF

RF busy

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Response

SOF

EOF