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Comment by userbinator | Hacker News Reader

From the name, I thought it would be a MediaTek product...

The 8051 is a very unusual architecture by contemporary standards, but is found in a surprisingly large amount of products and by some statistics, outsells ARM by a wide margin.

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The 8051 was originally developed by Intel but there were many second sources. It has a Harvard architecture so separate code and data memory space and furthermore an external memory space. Also can do single bit operations which is useful for controlling IO pins. Although an 8-bit processor, the compilers (like Keil which is now owned by ARM) are quite good. Not a days if I was wanting a low end micro-controller I would go with an ARM Cortex-M as the 32-bit CPU just makes programming a lot easier. I recall the days I spent micro optimizing a 32-bit multiply or divide on an older 8-bit CPU.

> Although an 8-bit processor, the compilers (like Keil which is now owned by ARM) are quite good.

Quite good? Keil's compiler is horrible. It produces large (2x too big) slow (2-4x too slow) binaries.

Which compiler would you recommend using instead?

I don't think there's a competent 8051 C compiler.

Compared to what?

Compared to handcoded assembler. To the level comparable to gcc -O3.

Handcoded assembly is slower to develop and it depending on the capabilities of the developer so there are tradeoffs. And is gcc available for an 8051?

Like I said, I wish 8051 had some good compiler. Like gcc.

No disagreement there that handcoded assembly is slower to develop! You do get code size below 50% and it runs twice as fast.

In the late 80's, I helped design a car on-board computer based on the 8052. PL/M was a fairly decent programming language.

I've done a bunch of 8051 projects, if you have to choose between ARM and 8051 - choose ARM!

8051 cores are cheap but they have weird memory hierarchies - managing them results in giant code, unless you're willing to break into assembly way too often

How relevant is it compared to, say, the 8-bit Atmel stuff, when it comes to new designs?

It's not relevant at all today. Use a 32-bit micro unless you've got a really good reason to do otherwise.

And cost isn't one of those reasons anymore.

As a standalone microcontroller, I'd agree. But as an IP core integrated to some design it is still quite relevant.

Or if you have low power requirements. The TI MSP430 really shines here.

The MSP430 really isn't that much lower power (if at all) than the Cortex M4 series nowadays.

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