[Arm-netbook] New Risc-V fully free chip

[Bill Kontos]

On Sun, Nov 19, 2017 at 5:44 AM, Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:

>  yeh the same team that was mentioned last week.  suggestions on how
> to contact them appreciated.

>From that link:

IF YOU ARE INTERESTED IN A EARLY ACCESS TO THE C-CLASS (64-BIT) PLEASE
MAIL US AT: Madhusudan : gs dot madhusudan at cse dot iitm dot ac dot
in Neel Gala : neelgala at gmail dot com

C class

32 and 64 bit 3-8 stage in-order core aimed at 10 Mhz - 1 Ghz
controller requiremenets
Optional memory protection and MMU
Very low power static design varinats
Fault Tolerant variants for ISO26262 applications
IoT variants will have compressed/reduced ISA support
Optional FPU, VPU
Bus - AHB variants

To me it looks like the first one is too slow for general purpose
computing, we would need the absolute maximum configuration to make
something useful as a desktop chip. The I class is probably better
suited.

I class

64-bit, 1-8 core, 8+ stage out of order, aimed at 200 Mhz - 2 Ghz
industrial control / general purpose applications
Shared L2 cache, dual threading support, SIMD/VPU
BUS - Shakti NoC + AXI4


This is the HN discussion:

https://news.ycombinator.com/item?id=15684225

The lead architect of this project( username gsmadhusudan) has some
more comments about it:

Yes, we will update the C Class next month since our private line has
a lot of foundry specific code that needs to be removed. The I class
needs more work but the design is in place. It will also move to quad
issue and would be a Cortex A72/75 class core. More importantly the
basic slow IPs, UART, I2C, quad/Octal SPI, SDRAM controller, JTAG,
DMA, PLIC will be FPGA and silicon proven and production quality. Will
be very useful to other developers (non RISC-V also) as would the AXI
bus.

Cortex A72 is a pretty big core that just made it into a phone thermal
budget with the first generation 16nm finfet process. One example is
the kirin 950( found in the huawei Mate 8). From anandtech's review
here are 2 links about power consumption:

https://images.anandtech.com/doci/9878/power-big.png
https://images.anandtech.com/doci/9878/CPUVolt.png

Full review here( and please don't ask me about non-free js on the
article): https://www.anandtech.com/show/9878/the-huawei-mate-8-review/3

Phones usually take around 3 watts tdp, so it looks like something of
this class could fit on an eoma68 card. Obviously the "optional
fpu-vpu" part remains a big question, while there also needs to be
someone who think they can sell a few million of these so they get
manufactured on a good enough node.