Stream Specialization Scheduler

About

• This library contains two major components, the config library which acts as a hardware description language, and the scheduler library for describing and scheduling dataflow graphs (DFG files) to the hardware.
• The simulator for the dataflow graph is currently embedded within the scheduler library.

Installation

Prerequisites

This repository requires a Python Version.

Building this repository

To build this repository, please follow the following steps:

First source the setup script from the main repo.

source ../setup.sh

Make the library by running:

make all

Command Reference

All scheduling functions are found through ss_sched command.

To run the scheduler, mapping a given dfg file to an adg file, run:

ss_sched [adg] [dfg]

To run the Design Space Explorer, run the following command:

ss_sched [adg] [dfg] -x

For a full reference of available options, run:

ss_sched --help

ADG Rules

Nodes

1. A spatial node's granularity must be [8, 16, 32, 64]

2. VectorPorts always have a granularity of 8 (byte-accessible).

3. A spatial node's datawidth must be a power of 2.

4. A vectorports datawidth is implicitly defined as the spatial links connected to it.

Example: VectorPort A has three links connecting to Switches X, Y, and Z. Switches X, Y, and Z have respective widths of 32, 32, and 64. Thus VectorPort A has a width of 32 + 32 + 64 = 128.

5. A node's granularity must be smaller than the spatial nodes datawidth

6. The number of slots of a node is defined as Node DataWidth / Node Granularity.

Links

1. A links granularity is max(source granularity, sink granularity)

2. The DataWidth of a link between two spatial nodes is max(source DataWidth, sink DataWidth).

3. The DataWidth of a link between vectorport and spatial node is the spatial nodes DataWidth.

4. The number of slots on a link is defined as Link DataWidth / Link Granularity

Link Connectivity

1. Two Nodes can't have two links in same direction between them.

Example:

• Invalid: NodeA->NodeB and NodeA->NodeB
• Valid: NodeA->NodeB and NodeB->NodeA

2. Two ADG Vector Ports can't have a link between each other.

3. An ADG Node can't have a recursive link.

4. A Spatial Node (Switch/PE) and Data Node (DMA/SPM) can't have a link between each other.

Mapping

1. Vertex slots must be mapped to even slots.

Example:

• Invalid: | | OPA | OPA | |
• Valid: | OPA | OPA | | |
• Valid: | | | OPA | OPA |

VectorPort Mapping

1. Two DFG ports can not be mapped to a single VectorPort.

2. The stated dfg edge is always 8 bits wide.

3. A stated DFG port can not be mapped to a non-stated vectorport.

4. The stated dfg edge is always mapped to a stated VectorPort on bits [0-8]. The first link of a vector port only includes the stated edge.

5. The other links of the vectorport are statically assigned according to their value id. A InputPort value can not stradle two different links.

Routing

1. Memory DFG Edges, or those with either their source or destination vertex being a data node, can't utilize switches.

Exampe:

• Invalid: SPM0 -> SWITCH0 -> IVP0

2. A dfg edge entering a non-switch must come in at an even slot

Example:

• Invalid: | | OPA | OPA | |
• Valid: | OPA | OPA | | |
• Valid: | | | OPA | OPA |

3. A switch can map to any contiguous slot.

Example:

• Valid: | | OPA | OPA | |
• Valid: | OPA | OPA | | |
• Valid: | OPA | | | OPA |
• Invalid: | OPA | | OPA | |

4. A lower bitwidth edge must always be mapped to the lower bits of a granularity.

Example: A 16 bit edge mapped to a Node with granularity 32 and datawidth 64 bit granularity

• Valid: Mapping edge to bits: [0:16] or [32:48]
• Invalid: Mapping edge to bits: [16:32] or [48:64]

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