Re: What is an N-bit machine?

On 12/2/2024 4:56 PM, Brian G. Lucas wrote:

On 12/2/24 3:48 AM, Terje Mathisen wrote:

MitchAlsup1 wrote:

On Sat, 30 Nov 2024 19:40:17 +0000, John Levine wrote:
>

I get the impression that we will have 32 bit architectures for a very
long time, since they are smaller and cheaper to implement than 64 bit
and for a lot of embedded applications they are more than adequate.
Examples are ARM Cortex-R4 and -R5, high performance 32 bit realtime
chips.

>
Still one hardly needs more than a Z80 to run a toaster, microwave,
stove,
oven, faucet, door lock, refrigerator, ... {{Or basically everything
nobody
ever thought would have/need a computer inside of them}}

>
They are still going to end up with a 32-bit CPU in future products!
>
Both because that's needed to support a full development environment/ arbitrary languages and because the cost is becoming mostly trivial:
>
When every single flash/thumb drive has contained a full 32-bit CPU for more than 5 years now, the cost has to be in the cents range.
>
Terje
>

Back in the early 1990s when my group first developed what would become the Motorola MCore, our target was radio (and cell phone) processors.  The intention was to replace the zoo of 16-bit hard to program processors with a 32-bit processor that was easy to program via compilers.  The additional address space was going to be needed for protocol stacks (such as IP/TCP) and support of USB stuff.  Even with the silicon nodes at the time, the resulting processor was not much bigger than bonding pads.
 I agree with Terje, no need to have anything less than 32-bit in embedded.

First, I want to apologize that in my previous post talking about everything going to 64 bits, I forgot about embedded markets.  Note that I used the plural form.  I haven't kept up with embedded markets since the 1990s, so things have probably changed.  But there are embedded markets with other requirements.  For example, for embedded applications such as remote controls (for e.g. TVs and set top boxes), battery life is very important, and pretty minimal functionality and performance are required, so they, at least used to use 4 bit processors.  Another example is the greeting cards that play music when opened.  There any cost more than a few pennies is too expensive.  So there are places where less than 32 bits is appropriate.
--
  - Stephen Fuld
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