STA2500D datasheet(39/57 Pages) STMICROELECTRONICS

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STA2500D

General specification

Doc ID 16067 Rev 1

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The combination of time division multiplexing and the priority mechanism avoids the

interference due to packet collision. It also allows the maximization of the 2.4 GHz ISM

bandwidth usage for both devices while preserving the quality of some critical types of link.

6.13.2

Algorithm 2: WLAN master

In case the STA2500D has to cooperate, in a collocated scenario, with a WLAN chip not

supporting a PTA based algorithm, it is possible to put in place a simpler mechanism.

The interface is reduced to 1 line:

Figure 14.

WLAN master

When the WLAN has to operate, it alerts high the BT_RF_NOT_ALLOWED signal and the

STA2500D will not operate while this signal stays high.

This mechanism permits to avoid packet collision in order to make an efficient use of the

bandwidth but cannot provide guaranteed quality over the Bluetooth links.

6.13.3

Algorithm 3: Bluetooth master

This algorithm represents the symmetrical case of algorithm 2. Also in this case the

interface is reduced to 1 line:

Figure 15.

Bluetooth master

When the STA2500D has to operate it alerts high the WLAN_RF_NOT_ALLOWED signal

and the WLAN will not operate while this signal stays high.

This mechanism permits to avoid packet collision in order to make an efficient use of the

bandwidth, it provides high quality for all Bluetooth links but cannot provide guaranteed

quality over the WLAN links.

6.13.4

Algorithm 4: two-wire mechanism

Based on algorithm 2 and 3, the Host decides, on a case-by-case basis, whether WLAN or

Bluetooth is master.The Master role can be checked and changed at run-time by the Host

via an HCI command.

STLC2500D

WLAN

BT_RF_NOT_ALLOWED

STLC2500D

WLAN

WLAN_RF_NOT_ALLOWED

STA2500D Folha de dados(PDF) 39 Page - STMicroelectronics