分布式同步的GALS片上网络及其接口设计

GALS Network-on-Chip with a distributed-synchronous mechanism

为了降低数据的传输延迟,提出了一种分布式同步方式实现全局异步局部同步(GALS)片上系统。该方式通过引入时钟来实现相邻网络节点之间的数据传输,使数据传输最小延迟由原来无时钟通信方式的4个线延迟减少到1个线延迟,大大降低了数据传输延迟。同时设计了支持该方式的跨时钟域接口。该接口不仅支持多路数据在同一物理链路中传输,而且允许在每个传输周期动态分配各路数据的带宽。仿真结果表明:支持4通道和16位宽数据的接口总共占用722个ALUT(adaptive look-up table)和支持204.5 MHz的时钟速率,占用较少面积和支持较高的时钟速率。

A distributed-synchronous mechanism was developed to implement globally asynchronous locally synchronous （GALS） Network-on-Chip to reduce transport latency. This mechanism enables clock control data transport in the control of clock, so the minimum transporting delay can be reduced from 4Δ （wire delay） to 1Δ. An asynchronous interface was designed to support the distributed-synchronous mechanism. The asynchronous interface supports multiple channels, enables dynamic bandwidth allocations between channels in every data transport cycle. An interface with four 16 bit channels required 722 adaptive look-up tables and ran at 204.5 MHz. Simulation results show that the interface supports high data rate at reasonable complexity.