By: Rob Thorpe (rthorpe.delete@this.realworldtech.com), June 28, 2007 5:15 am
Room: Moderated Discussions
JS (JS@NOSPAM.COM) on 6/28/07 wrote:
---------------------------
>Rob Thorpe (rthorpe@realworldtech.com) on 6/28/07 wrote:
>---------------------------
>>>I'd expect other CPU's to generally have more errata
>>>than most commodity x86 chips.
>>
>>Well, most other CPUs are embedded ones. As I understanding it, the 32-bit processor
>>cores that can be bought as cores, like ARMs & ARCs, have very few errata. Correct
>>operation is such an important feature. And they are also much simpler than x86s.
>
>ARM is sold in such quantities that it can not be used as
>an example here to prove your point.
>I think you have overlooked the amount of embedded CPUs
>which have a short lifetime, and where the CPU and compiler
>often come from the same vendor. Just talk to people who
>have to make a project work with a newly released embedded
>CPU - they are not always happy. They have (ASM) to avoid
>certain constructs, the compiler has to do this as well
>for C ...
Indeed, those are often complete junk. I worked next-door to a place that did smart card programming for a bit. Whenever they targetted an obscure microprocessor they found bugs.
>I certainly agree with Linus.
Well, by volume most other CPUs are ARMs, PICs, 8051s and TI DSPs. All of these are simpler than x86s, have being around for years and are used in critical situations. I expect almost all of these have fewer errata than x86s.
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>Rob Thorpe (rthorpe@realworldtech.com) on 6/28/07 wrote:
>---------------------------
>>>I'd expect other CPU's to generally have more errata
>>>than most commodity x86 chips.
>>
>>Well, most other CPUs are embedded ones. As I understanding it, the 32-bit processor
>>cores that can be bought as cores, like ARMs & ARCs, have very few errata. Correct
>>operation is such an important feature. And they are also much simpler than x86s.
>
>ARM is sold in such quantities that it can not be used as
>an example here to prove your point.
>I think you have overlooked the amount of embedded CPUs
>which have a short lifetime, and where the CPU and compiler
>often come from the same vendor. Just talk to people who
>have to make a project work with a newly released embedded
>CPU - they are not always happy. They have (ASM) to avoid
>certain constructs, the compiler has to do this as well
>for C ...
Indeed, those are often complete junk. I worked next-door to a place that did smart card programming for a bit. Whenever they targetted an obscure microprocessor they found bugs.
>I certainly agree with Linus.
Well, by volume most other CPUs are ARMs, PICs, 8051s and TI DSPs. All of these are simpler than x86s, have being around for years and are used in critical situations. I expect almost all of these have fewer errata than x86s.
