The integrated IP core for Interlaken handles all protocol related functions to communicate to the other devices Interlaken interface. All handshaking, synchronizing, and error checking are handled by the Interlaken IP core. You can provide packet data through the local bus (LBUS) TX interface and receive it from the LBUS RX interface. The LBUS is designed to match packet bus protocols made common by the SPI4.2 protocol; a detailed description is provided in Designing with the Core.
The Interlaken IP core is designed to be as flexible as possible and to be used in many different applications. As such, the Interlaken IP core provides all of the flexibility offered by the Interlaken protocol. Flow control information is automatically extracted by the RX path of the Interlaken IP core. You must monitor the flow control information and ensure proper data transmission through the core. Also, the Interlaken IP core TX path consists of a single pipeline with a single memory buffer. You must build the enhanced scheduling algorithm block external to the Interlaken IP core.
The following is an example:
The operation steps after the Interlaken IP core is powered up are as follows:
- After the device is powered up and the reset procedure completed, the Interlaken IP core TX path starts transmitting Control/Idle words to align and synchronize the receiving device Interlaken interface. Similarly, the Interlaken IP core RX path receives Control/Idle words and completes its own synchronization procedure.
- You must set all of the flow control inputs to the Interlaken IP core TX path to the XOFF state to prevent any real data transfer.
- The RX path becomes synchronized and aligned, and signals the user logic that alignment is complete. You can then turn the flow control information from XOFF to XON for any of the channels that are ready to accept data.
- When the other device is ready to receive data, it sends XON information to the Interlaken IP core. The Interlaken IP core signals the user logic which channels can be used for data transmission.
These steps provide a simple and easily implemented procedure for using the Interlaken IP core. You build a scheduler to multiplex data among the different logical channels and use the flow control information output by the Interlaken IP core to manage the scheduling function. You do not need to be concerned with any of the lower level Interlaken protocol details.