TI MSP430
in [Embedded]
|
From: larwe on 8 Apr 2006 20:43 Marc Ramsey wrote: > > MSP430 is a truly elegant architecture, there's no denying it. von > > Of course, the architecture is a simplified version of the TMS9900 CPU, > which was derived from the TI 990 minicomputer, which was in turn a > rip-off of the PDP-11 ISA, with slight changes (fewer addressing modes, LOL. You know, writing this most recent book is so amusing. I think I could probably use 75% of it as responses in c.a.e. "Now, it's an obscure but well-recognized ritual amongst engineers and computer scientists to gauge the architecture of any new device on the basis of its similarity to the PDP-11(1). The strongest term of approbation you can use for a CPU design is to say "It's just like a PDP-11!". Exactly why this is universally regarded as a Good Thing is not exactly clear, but in any case, this epithet is frequently applied to the MSP430. (I've always felt that this is the same sort of statement as saying "My 2007 Mercedes convertible is just like a 1965 International Harvester Scout light truck. They both have pneumatic tires and a removable roof!"). What I think these people probably mean is that the MSP430 has a very nice orthogonal instruction set and simple memory addressing scheme. (1) - If I ever design a microprocessor, I am going to print a line drawing of a complete PDP-11/20 front panel on the top of the package."
From: Jim Granville on 8 Apr 2006 20:47 larwe wrote: > Grant Edwards wrote: > > >>>>>The MSP430 prices are annoying, though. AVRs come down to >>>>>as little as 1/4th the price of an equivalent TI part. >>>> >>>>In what volumes ? >>> >>>30~50K annually. >> >>You must get a better deal on AVR parts than I could. I was That can happen, where one supplier is able to get better "column movement" than another. Plus lead free 'stock clearing' can also affect prices... > I can buy an ATmega32L cheaper than an MSP430F1122... > Just looking at Mouser prices, (which are low volume), MSP430F1122IDW MSP430 Series SOIC-20 4kB Flash 256B RAM 10bit ADC 250: $ 3.000 ATMEGA32L-8MC Atmel RISC Microcontrollers MLF-44 32k byte 100: $ 8.010 C8051F411-GM Mixed Signal MLP28 50 MIPS,32KB,12ADC RTCLOCK,28 PIN,MCU 1: $ 3.670 -jg
From: larwe on 8 Apr 2006 20:55 Jim Granville wrote: > That can happen, where one supplier is able to get better > "column movement" than another. > Plus lead free 'stock clearing' can also affect prices... We buy direct in both cases, and we only spec in RoHS-compliant parts. > Just looking at Mouser prices, (which are low volume), Right. But these are distribution prices. They don't reflect the direct pricing at all. Clearly TI's prices to distris are closer to the break-even edge than Atmel's, so neither TI nor the distri have much room to discount deeply on quantity.
From: Grant Edwards on 8 Apr 2006 21:31 On 2006-04-08, larwe <zwsdotcom(a)gmail.com> wrote: > > Grant Edwards wrote: > >> >> > The MSP430 prices are annoying, though. AVRs come down to >> >> > as little as 1/4th the price of an equivalent TI part. >> >> >> >> In what volumes ? >> > >> > 30~50K annually. >> >> You must get a better deal on AVR parts than I could. I was > > I can buy an ATmega32L cheaper than an MSP430F1122... IIRC, I was comparing ATmega6450 and ATmega1280 with 430F148 and 149. The AVR parts were quite a bit more expensive ($2-$3 more). -- Grant Edwards grante Yow! O.K.! Speak with a at PHILADELPHIA ACCENT!! Send visi.com out for CHINESE FOOD!! Hop a JET!
From: larwe on 8 Apr 2006 22:02
Grant Edwards wrote: > > I've worked a lot with AVR in my real life, and MSP430 mostly > > at work. While AVR is not internally as tidy as MSP430, it's > > really not bad > > As long as you close your eyes and force yourself not to look > at the code a compiler has to generate for pointer-intensive Oh, AVR ain't so bad. Most of the irritations stem from the different handling of r16-r31 and the fact that X,Y,Z are (a) different from one another, and (b) the only 16-bit regs. If they had been able to implement it such that every register was part of a register pair (and every register pair able to act as a pointer), it would have been much better. But that's where a 16-bit instruction word (and not being a slave to the RISC idea of one word per instruction) comes in handy. > through to reserve space on the stack for auto variables. IIRC, > it has to disable interrupts while it does multiple 8-bit I/O > operations because the stack pointer isn't directly accessible > as a register. There are ways around this, e.g. using a separate stack implemented in software. > The dearth of registers that can be used as pointers is also > rather C-hostile. Well, yes - I didn't say it was perfect. |