[gsmecher]

According to a Reddit comment [1], this is the same MicroBlaze RTL with a RISC-V instruction decoder in front of it. This seems crazy from a let's-make-the-best-RISCV-core perspective, but that's never been Xilinx/AMD's goal.

MicroBlaze has always been a great example of a boring in-order RISC CPU in a boring niche. For an FPGA vendor, soft cores are loss leaders: they sell silicon but don't make money on their own. They are also boring technology: they are "integration glue", and don't belong in the portion of the FPGA that drives performance. "Good enough" is good enough.

If AMD really is reusing MicroBlaze RTL, then they're able to keep their existing firmware (core, FPU, debug, peripherals, etc) and software (HAL, compiler, drivers). These are all highly desirable from the perspective of the vendor, and any users looking for a painless transition to the new MicroBlaze core.

1: https://old.reddit.com/r/FPGA/comments/17mdcyt/microblaze_go...

[brucehoult]

That Redditor has -5 karma. Also that idea makes pretty much zero sense when it's a matter of a couple of days to implement a simple RISC-V core from scratch.

I would not rely on that information.

It does, however, have the same external interface as Microblaze and hardware wise is a drop in replacement in existing designs.

[gsmecher]

I posted the Reddit link because it wasn't my insight - but I agree it's a dubious source. That doesn't make it wrong. (I'm not certain it's right, either - it's an interesting claim.)

A RV32I core is easy to implement from scratch, but Microblaze-V already has a single-precision FPU, and it will need an MMU to reach feature parity. It's much bigger than a weekend project to produce a RISC-V core that's feature-matched with MicroBlaze.

[SilverBirch]

> For an FPGA vendor, soft cores are loss leaders: they sell silicon but don't make money on their own.

This is dead right, the enabling technologies like this don’t make money in their own right so they aren’t considered valuable in hardware companies. It’s why the billionaire CEOs of Xilinx and Altera shake their heads ruefully when they hear Jenson Huang continue to throw money away on nvidias software stack. One day he’ll learn where the real value is.

[gsmecher]

> This is dead right, the enabling technologies like

You fundamentally misunderstand. Soft core CPUs aren't enabling technologies and haven't been for decades. They are plumbing, like FIFO or SERDESes. You can't sell an FPGA into most markets without them.

[GeorgeTirebiter]

I sense just a bit of snark here ;-) Jenson Huang is clearly a visionary genius regarding GPU compute. I thought software ate the world?