First Cortex-M3 MCUs available
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From: Eric on 4 Apr 2006 15:10 >Their errata says 1.7mA, so no, it is not MSP430 area. Thanks for that tip to look at errata. Sometimes I don't pay attention to it, and I really should, of course. I see 35 ma as typical full speed operating current in the spec sheet (3.3v @ 20Mhz), and 1.7 ma in deep sleep. This is definitely not a candidate for battery power. The lpc2103 has better numbers than these, and the new lpc2888 is supposed to be able to operate from a single 1.5v battery. This is still an interesting device and I'll likely get the new dev board from Rowley and check it out. But it lacks the main advantage I was looking for. Eric
From: Jim Granville on 5 Apr 2006 15:48 Eric wrote: >>Their errata says 1.7mA, so no, it is not MSP430 area. > > > Thanks for that tip to look at errata. Sometimes I don't pay attention > to it, and I really should, of course. > > I see 35 ma as typical full speed operating current in the spec sheet > (3.3v @ 20Mhz), and 1.7 ma in deep sleep. > > This is definitely not a candidate for battery power. The lpc2103 has > better numbers than these, and the new lpc2888 is supposed to be able > to operate from a single 1.5v battery. > > This is still an interesting device and I'll likely get the new dev > board from Rowley and check it out. But it lacks the main advantage I > was looking for. If you are looking for better maths, and low power, the metering market has some focused devices - and they need reasonable maths to get accurate powers. Companies like TDK have a C51 + CoPro, and Maxim has their MAXQ, they claim is lowest power 16 bit CPU - but the mA/MHz need to be watched on some models. If you want real speed, in a new 32 bit core see http://www10.edacafe.com/nbc/articles/view_article.php?section=ICNews&articleid=257140 ( the SH2A, like Cortex, claims better code size (25% smaller), but unlike the first Cortex-M3, hits ~160MHz and also claims "(Upward instruction compatibility is maintained with the SH-2 core.)" -jg
From: Andrew M on 5 Apr 2006 17:47 want real speed, in a new 32 bit core see > > http://www10.edacafe.com/nbc/articles/view_article.php?section=ICNews&articleid=257140 > > ( the SH2A, like Cortex, claims better code size (25% smaller), but > unlike the first Cortex-M3, hits ~160MHz and also claims "(Upward instruction > compatibility is maintained with the SH-2 core.)" > > -jg > > > It's important to note that the core mA/MHz figure is almost irrelevant for low power, low on-cycle applications. Sure, the MSP430 has a low mA/MHz figure but the clock ramp-up and flexibility, smart peripherals, low pin leakage are more important. To chase low mA/MHz figures is naive for real applications unless the device spends a lot of time at full power. The MSP430 is still very hard to beat for low on-cycle, low power applications. -Andrew M
From: Wilco Dijkstra on 5 Apr 2006 18:43 "Jim Granville" <no.spam(a)designtools.co.nz> wrote in message news:44341ef4(a)clear.net.nz... > Eric wrote: > If you want real speed, in a new 32 bit core see > > http://www10.edacafe.com/nbc/articles/view_article.php?section=ICNews&articleid=257140 > > ( the SH2A, like Cortex, claims better code size (25% smaller), but > unlike the first Cortex-M3, hits ~160MHz and also claims "(Upward > instruction compatibility is maintained with the SH-2 core.)" A few new instructions (they mention bitfield and division) isn't going to give 25% average codesize improvement. Few instructions improve codesize by more than 1% (bitfield instructions give far less), so you do need to do something drastic to get to 25%. It's interesting to note that Renesas recently licensed some ARM cores. A similar MCU was announced by Philips (208Mhz ARM926EJ-S with floating point hardware and Java acceleration): http://www.standardics.philips.com/news/lpc3180/~LPC3180/#top It looks like everybody is going after the high-end MCU (100+Mhz) segment. Wilco
From: Jim Granville on 5 Apr 2006 21:14
Wilco Dijkstra wrote: > "Jim Granville" <no.spam(a)designtools.co.nz> wrote in message > news:44341ef4(a)clear.net.nz... > >>Eric wrote: > > >>If you want real speed, in a new 32 bit core see >> >>http://www10.edacafe.com/nbc/articles/view_article.php?section=ICNews&articleid=257140 >> >>( the SH2A, like Cortex, claims better code size (25% smaller), but >>unlike the first Cortex-M3, hits ~160MHz and also claims "(Upward >>instruction compatibility is maintained with the SH-2 core.)" > > > A few new instructions (they mention bitfield and division) isn't going to > give 25% average codesize improvement. Few instructions improve > codesize by more than 1% (bitfield instructions give far less), so you > do need to do something drastic to get to 25%. > > It's interesting to note that Renesas recently licensed some ARM cores. > > A similar MCU was announced by Philips (208Mhz ARM926EJ-S with > floating point hardware and Java acceleration): > > http://www.standardics.philips.com/news/lpc3180/~LPC3180/#top > > It looks like everybody is going after the high-end MCU (100+Mhz) > segment. True. What sets the SH2A appart a little from the others (AVR32, LPC3180 Fujitsu, Freescale etc), is the SH2A claims 160MHz/320 MIPS from internal flash(512KF). Most other internal flash specs are 50/60/80MHz region. Flash has always been a weakspot, and flash has been getting faster slower than the cores. Analog Devices dumped their FLASH DSPs, and went for RAM cores instead. -jg |