A multi processor PIC computer :-)
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From: John Larkin on 11 Jun 2010 11:35 On Fri, 11 Jun 2010 15:24:34 +0100, John Devereux <john(a)devereux.me.uk> wrote: >John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: > >> On Thu, 10 Jun 2010 22:36:32 -0500, "krw(a)att.bizzzzzzzzzzzz" >> <krw(a)att.bizzzzzzzzzzzz> wrote: >> >> >>>>>>Here's the board. >>>>>> >>>>>>ftp://jjlarkin.lmi.net/V220.gif >>>>>> >>>>>>The 12 ARMs run down the middle. To their right are the data >>>>>>isolators, regulators, jtag connector, and dc/dc converter. The analog >>>>>>stuff is to the left. >>>>>> >>>>>>This is a 12-channel 4-20 mA sort of i/o board. >>>>> >>>>>How many I/O per channel? >>>> >>>>Each channel has just two pins. Any channel can >>>> >>>>source 0-24 mA or 0-20 volts, CV/CC >>>> >>>>Regulate an external current loop, 0-32 mA >>>> >>>>Measure an external current loop, 0-32 mA >>>> >>>>Measure voltage (actually, it always measures current and voltage) >>>> >>>>Be an open. >>>> >>>>Be a short. >>> >>>Doesn't sound like a lot of data or computation. Wouldn't it have been >>>simpler to isolate between the DAC and the CPU? That is, one processor? >> >> Each little CPU has a multiplexed ADC and a DAC in it, and the SPI >> stuff, and a bunch of parallel ports. That's cheaper than putting a >> separate ADC and DAC and ports up there. The CPU part is essentially >> free. We use the individual, isolated CPUs to do the closed-loop >> control, measurement, protections, and SPI up/down. The local control >> loops will each run at 50 or 100K hits/second. If we did SPI up/down >> to a single CPU, it couldn't run that fast, and the SPI traffic would >> get huge if we tried. >> >> It is a little weird to think of getting a 100 MHz, 32-bit ARM CPU, >> with RAM and flash, essentially for free when you buy the ADC and DAC. > >44MHz, aren't they? Or have you found a new one? We're using the 80-pin LPC1758 in the channels. I think it runs at 100 MHz max. ================ The LPC1758/56/57/54/52/51 operate at CPU frequencies of up to 100 MHz. The LPC1759 operates at CPU frequencies of up to 120 MHz. The ARM Cortex-M3 CPU incorporates a 3-stage pipeline and uses a Harvard architecture with separate local instruction and data buses as well as a third bus for peripherals. The ARM Cortex-M3 CPU also includes an internal prefetch unit that supports speculative branching. The peripheral complement of the LPC1759/58/56/54/52/51 includes up to 512 kB of flash memory, up to 64 kB of data memory, Ethernet MAC, USB Device/Host/OTG interface, 8-channel general purpose DMA controller, 4 UARTs, 2 CAN channels, 2 SSP controllers, 2 2 SPI interface, 2 IC-bus interfaces, 2-input plus 2-output I S-bus interface, 6 channel 12-bit ADC, 10-bit DAC, motor control PWM, Quadrature Encoder interface, 4 general purpose timers, 6-output general purpose PWM, ultra-low power Real-Time Clock (RTC) with separate battery supply, and up to 52 general purpose I/O pins. ============== That is truly insane for $6 or so. One of the NXP arms is under $1. John
From: John Devereux on 11 Jun 2010 17:26 John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: > On Fri, 11 Jun 2010 15:24:34 +0100, John Devereux > <john(a)devereux.me.uk> wrote: > >>John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: >> >>> On Thu, 10 Jun 2010 22:36:32 -0500, "krw(a)att.bizzzzzzzzzzzz" >>> <krw(a)att.bizzzzzzzzzzzz> wrote: >>> >>> >>>>>>>Here's the board. >>>>>>> >>>>>>>ftp://jjlarkin.lmi.net/V220.gif >>>>>>> >>>>>>>The 12 ARMs run down the middle. To their right are the data >>>>>>>isolators, regulators, jtag connector, and dc/dc converter. The analog >>>>>>>stuff is to the left. >>>>>>> >>>>>>>This is a 12-channel 4-20 mA sort of i/o board. >>>>>> >>>>>>How many I/O per channel? >>>>> >>>>>Each channel has just two pins. Any channel can >>>>> >>>>>source 0-24 mA or 0-20 volts, CV/CC >>>>> >>>>>Regulate an external current loop, 0-32 mA >>>>> >>>>>Measure an external current loop, 0-32 mA >>>>> >>>>>Measure voltage (actually, it always measures current and voltage) >>>>> >>>>>Be an open. >>>>> >>>>>Be a short. >>>> >>>>Doesn't sound like a lot of data or computation. Wouldn't it have been >>>>simpler to isolate between the DAC and the CPU? That is, one processor? >>> >>> Each little CPU has a multiplexed ADC and a DAC in it, and the SPI >>> stuff, and a bunch of parallel ports. That's cheaper than putting a >>> separate ADC and DAC and ports up there. The CPU part is essentially >>> free. We use the individual, isolated CPUs to do the closed-loop >>> control, measurement, protections, and SPI up/down. The local control >>> loops will each run at 50 or 100K hits/second. If we did SPI up/down >>> to a single CPU, it couldn't run that fast, and the SPI traffic would >>> get huge if we tried. >>> >>> It is a little weird to think of getting a 100 MHz, 32-bit ARM CPU, >>> with RAM and flash, essentially for free when you buy the ADC and DAC. >> >>44MHz, aren't they? Or have you found a new one? > > We're using the 80-pin LPC1758 in the channels. I think it runs at 100 > MHz max. > > > That is truly insane for $6 or so. One of the NXP arms is under $1. Oh yes, nice looking chip, will be using it myself soon. Sorry, I thought you were using ADUC7000 series for some reason. They do match the description of a good ADC and DAC with a free ARM attached, although not such a good one. [...] -- John Devereux
From: krw on 11 Jun 2010 20:29
On Thu, 10 Jun 2010 21:21:53 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 10 Jun 2010 22:36:32 -0500, "krw(a)att.bizzzzzzzzzzzz" ><krw(a)att.bizzzzzzzzzzzz> wrote: > > >>>>>Here's the board. >>>>> >>>>>ftp://jjlarkin.lmi.net/V220.gif >>>>> >>>>>The 12 ARMs run down the middle. To their right are the data >>>>>isolators, regulators, jtag connector, and dc/dc converter. The analog >>>>>stuff is to the left. >>>>> >>>>>This is a 12-channel 4-20 mA sort of i/o board. >>>> >>>>How many I/O per channel? >>> >>>Each channel has just two pins. Any channel can >>> >>>source 0-24 mA or 0-20 volts, CV/CC >>> >>>Regulate an external current loop, 0-32 mA >>> >>>Measure an external current loop, 0-32 mA >>> >>>Measure voltage (actually, it always measures current and voltage) >>> >>>Be an open. >>> >>>Be a short. >> >>Doesn't sound like a lot of data or computation. Wouldn't it have been >>simpler to isolate between the DAC and the CPU? That is, one processor? > >Each little CPU has a multiplexed ADC and a DAC in it, and the SPI >stuff, and a bunch of parallel ports. That's cheaper than putting a >separate ADC and DAC and ports up there. The CPU part is essentially >free. We use the individual, isolated CPUs to do the closed-loop >control, measurement, protections, and SPI up/down. The local control >loops will each run at 50 or 100K hits/second. If we did SPI up/down >to a single CPU, it couldn't run that fast, and the SPI traffic would >get huge if we tried. > >It is a little weird to think of getting a 100 MHz, 32-bit ARM CPU, >with RAM and flash, essentially for free when you buy the ADC and DAC. Yes, I see your point. That is amazing. |