AT90S8515 and 8051?

[Sam Kaan]

How compatible is the AT90S8515 microcontroller to the 8051? I read
that they both have 40 pins but the 8515 runs much faster than the
8051. Are the codes that were originally written for 8051 opcode
compatible with the AT90S8515? any comments?

 

[Meindert Sprang]

How compatible is the AT90S8515 microcontroller to the 8051? I read
that they both have 40 pins but the 8515 runs much faster than the
8051. Are the codes that were originally written for 8051 opcode
compatible with the AT90S8515? any comments?

Well, the pin layouts are fairly "compatible" with respect to the positions
of the generic I/O pins and bus expansion. But that's about is. They are
absolutely not code compatible and their architecture is very different. To
give you a speed comparison: a software UART I once wrote was 14 times
faster on the AVR.

Meindert

 

[Roger Lascelles]

AT90S8515-4 (obsolete for new designs) Code Memory = 8kB, RAM = 512B
EERAM = 512B

This is one of the AVR (8 bit RISC) series. Atmel do make 8051 compatible
parts, but this is not one of them.

For the same task, the AVR parts use less instruction memory and get more
done per instruction . Often you can run AVR slower for reduced EMI and
power consumption. The AVR parts are designed for compiled ( C, Basic,
Pascal etc) code and are heaps more efficient with compiled code than a
standard 8051.

If you have an investment in 8051 code and don't want to rewrite it, there
is a large choice of 8051 instruction set parts. Cygnal have very fast 8051
code-compatible chips.

Roger

 

[RA]

Not compatible. For 8051 architecture use
AT80C5xxx,AT83C5xxx,AT89Cxxxx etc. if you want
to use Atmel devices, otherwise check DS80C310 or
DS89C420 at Maxim web site.
The AT90S/Lxxxx series are AVR 8-bit RISC devices.
best regards
RA

 

[Sam Kaan]

AT90S8515-4 (obsolete for new designs) Code Memory = 8kB, RAM = 512B
EERAM = 512B

This is one of the AVR (8 bit RISC) series. Atmel do make 8051 compatible
parts, but this is not one of them.

For the same task, the AVR parts use less instruction memory and get more
done per instruction . Often you can run AVR slower for reduced EMI and
power consumption. The AVR parts are designed for compiled ( C, Basic,
Pascal etc) code and are heaps more efficient with compiled code than a
standard 8051.

If you have an investment in 8051 code and don't want to rewrite it, there
is a large choice of 8051 instruction set parts. Cygnal have very fast 8051
code-compatible chips.

Roger

How widely used are the AT90Sxxxx (these RISC ones) series in the
automotive or consumer appliances industry or other industry then? Is
it a good idea to bother to learn for as far as improving your job
skills is concerned?

 

[Roger Lascelles]

How widely used are the AT90Sxxxx (these RISC ones) series in the
automotive or consumer appliances industry or other industry then? Is
it a good idea to bother to learn for as far as improving your job
skills is concerned?

If you have, say an AVR development kit or some chips, that is a great way
to learn. If you have a specific task, you will want to look at a few
different micros and make a decision on price, availability, available
skills, local distributors etc.

I use the AVR micros and have had a good time. I can program in C with the
free GCC compiler and need next to no assembler, so my code is better
quality and gets working faster. This means I can quickly target a job and
get it finished.

The AVRs have heaps of speed, plenty of upgrade options for bigger jobs and
enough RAM and EE . Its a different feeling to the days when you had to
force the last ounce out of a microcontroller. Onboard timers, Analog to
Digital converter, pulse width modulation, serial port for RS232 are things
I use.

The AVRs have a decent share of the market, and you will find them in
various products. The 8051 compatibles would be the best sellers of all.
8051 parts are not exactly inspiring, but they will be with us for a long
time yet.

If you learn to program one micro, you will be able to switch to another.
All micros have the same issues - setting bits in configuration registers,
using timers, ports.

Roger