DATA MERGING FOR BLUETOOTH DEVICES
A method for performance in a device having a first processing system for providing the functionality of the upper layers of a Bluetooth stack and a Bluetooth Controller for providing the functionality of the lower layers of the Bluetooth stack, the first processing system and the Bluetooth Controller being connected by a Host Controller Interface (HCI), the method including the steps of generating L2CAP packets in the L2CAP layer of the Bluetooth stack in the first processing system corresponding to an Asynchronous Connectionless (ACL) link, transmitting those L2CAP packets through the Bluetooth stack to the Bluetooth Controller via the HCI, inserting data generated in a second processing system into the L2CAP packets in the Bluetooth Controller, and transmitting the L2CAP packets over the ACL link.
1 . A method for performance in a device having a first processing system for providing the functionality of the upper layers of a Bluetooth stack and a Bluetooth Controller for providing the functionality of the lower layers of the Bluetooth stack, the first processing system and the Bluetooth Controller being connected by a Host Controller Interface (HCI), the method comprising the steps of
generating L2CAP packets in the L2CAP layer of the Bluetooth stack in the first processing system corresponding to an Asynchronous Connectionless (ACL) link,
transmitting those L2CAP packets through the Bluetooth stack to the Bluetooth Controller via the HCI,
inserting data generated in a second processing system into the L2CAP packets in the Bluetooth Controller, and
transmitting the L2CAP packets over the ACL link.
2 . A method according to claim 1 , wherein inserting data comprises overwriting existing payload data.
3 . A method according to claim 1 , wherein inserted data comprises adding payload data to existing header data.
4 . A method according to claim 1 wherein the L2CAP packets are generated to transport data output by an application on the first processing system.
5 . A method according to claim 4 , wherein the data output from the application on the first processing system is at a rate and timing to match the data generated in the second processing system.
6 . A method according to claim 4 , wherein the data output from the application on the first processing system is at an average data rate equal to the average data rate of the data generated by the DSP.
7 . A method according to claim 1 , wherein the capacity and timing of the L2CAP packets matches the timing and rate of the data generated by the DSP.
8 . A method according to claim 1 , wherein the average capacity over time of the L2CAP packets matches the average data rate of the data generated by the DSP.
9 . A method according to claim 8 , wherein the L2CAP packets are generated in batches.
10 . A method according to claim 9 , wherein the number of L2CAP packets generated in a batch is less than the permissible number of L2CAP packets, as determined by flow control in layers beneath L2CAP.
11 . A method according to claim 9 , wherein the number of L2CAP packets generated in a batch is in excess of the capacity of the transmission buffers in the Bluetooth controller.
12 . A method according to claim 1 , wherein the data generated on the DSP is decoded audio data generated by decoding an audio file.
13 . A method according to claim 1 , wherein the first processing system is a host processor.
14 . A method according to claim 1 , wherein a user interface and control functions of a music decoding system are provided by the first processing system.
15 . A method according to claim 14 , further comprising the step of the first processing system opening the ACL link to which the L2CAP packets relate and indicating the identity of that ACL link to the DSP.
16 . A method according to claim 15 , wherein the L2CAP packets for insertion into are identified by comparison of the L2CAP header information with the identity of the ACL link transmitted to the DSP.