> There are multiple TPU vendors
There are not - TPU is literally a Google trademark:
> Tensor Processing Unit (TPU) is an AI accelerator application-specific integrated circuit (ASIC) developed by Google.
https://en.wikipedia.org/wiki/Tensor_Processing_Unit
The rest of what you're talking about is irrelevant
"A Brief Guide of xPU for AI Accelerators" https://www.sigarch.org/a-brief-guide-of-xpu-for-ai-accelera...
NPU: Neural Processing Unit: https://en.wikipedia.org/wiki/Neural_processing_unit
Coprocessor: https://en.wikipedia.org/wiki/Coprocessor