Snitch Cluster

This ip contains a cluster of Snitch cores, arranged in a specific (but configurable fashion).

Memory Map

The memory map of the cluster is determined by the cluster_base_addr_i signal. Depending on the amount of memory the TCDM and Periph regions will be scaled accordingly. The peripheral region will always be the same size as the TCDM.

• Let TCDMSize denote the size of the TCDM.
• Let PeripheralSize denote the size of the cluster peripheral address space.
• Let TCDMEndAddress = cluster_base_addr_i + TCDMSize
• Let SocEndAddress = TCDMEndAddress + PeripheralSize

Range	Dest	Description
[SocEndAddress - )	SoC	Routed out of the cluster. Address range depends on available address bits.
[TCDMEndAddress - SocEndAddress)	Periph	Cluster local peripherals.
[cluster_base_addr_i - TCDMEndAddress)	TCDM	Cluster local tightly coupled data memory.
[0x0 - cluster_base_addr_i)	SoC	Routed out of the cluster.

Info

Because the address check on each core's LSU path is quite critical, we rely on a simplified checking scheme were we revert to checking the address against a mask and base combination. This makes the hardware less expensive (and faster) as no complicated adder circuits are needed and a couple of and gates are enough. (In comparison to a full address check where two adders are need)

assign match = (addr_base & addr_mask) == (addr_to_check & addr_mask);

As a consequence the cluster_base_addr_i has to be aligned to the the TCDM size, otherwise this check can't distinguish between routing to the TCDM or SoC/Periph. A static assertion checks that this holds true.