In comp.arch.fpga, Antti.Lukats@googlemail.com <Antti.Lukats@googlemail.com> wrote:> > and.. i do not like any wires direct to FPGA or MCU either (going off > board/cable), > have seen a Atmel to bulk erase itself because the reset line was > in 2 meter long cable parallel to wire carrying 12V (reed relay > switched) > (well Atmel claimed such bulk erase is impossible... > but it happened twice and second time i had another > guy to witness it, so i wasnt seeing ghosts)A little off-topic perhaps, but now i'm curious. What atmel chip did you experience this erase with? We have just experienced a few spontanious erases (over a couple of months) of the first sector of an atmel dataflash on one of our boards. Another board in the same system uses a dataflash for MCU code and one for FPGA configuration and we have not had trouble with those. -- Stef (remove caps, dashes and .invalid from e-mail address to reply by mail) New York's got the ways and means; Just won't let you be. -- The Grateful Dead
FPGA LVDS for AC-decoupled transmit over CAT-5 cable
Started by ●March 11, 2009
Reply by ●March 12, 20092009-03-12
Reply by ●March 12, 20092009-03-12
On Mar 12, 10:20=A0pm, Stef <stef...@yahooI-N-V-A-L-I-D.com.invalid> wrote:> In comp.arch.fpga, > > Antti.Luk...@googlemail.com <Antti.Luk...@googlemail.com> wrote: > > > and.. i do not like any wires direct to FPGA or MCU either (going off > > board/cable), > > have seen a Atmel to bulk erase itself because the reset line was > > in 2 meter long cable parallel to wire carrying 12V (reed relay > > switched) > > (well Atmel claimed such bulk erase is impossible... > > but it happened twice and second time i had another > > guy to witness it, so i wasnt seeing ghosts) > > A little off-topic perhaps, but now i'm curious. What atmel chip did > you experience this erase with? We have just experienced a few > spontanious erases (over a couple of months) of the first sector of an > atmel dataflash on one of our boards. Another board in the same system > uses a dataflash for MCU code and one for FPGA configuration and we have > not had trouble with those. > > -- > Stef =A0 =A0(remove caps, dashes and .invalid from e-mail address to repl=y by mail)> > New York's got the ways and means; > Just won't let you be. > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 -- The Grateful Deadit was the VERY first samples of ATmega32 those samples had m32 written with pencil on top no i am lying, it was atmega163 and we tried to program those m32 the erasure did erase ALL memory, application sector and boot sector at same time, and there is no IAP command todo that.. so it should never happen Antti
Reply by ●March 12, 20092009-03-12
In comp.arch.fpga, Antti.Lukats@googlemail.com <Antti.Lukats@googlemail.com> wrote:> On Mar 12, 10:20�pm, Stef <stef...@yahooI-N-V-A-L-I-D.com.invalid> > wrote: >> In comp.arch.fpga, >> >> Antti.Luk...@googlemail.com <Antti.Luk...@googlemail.com> wrote: >> >> > and.. i do not like any wires direct to FPGA or MCU either (going off >> > board/cable), >> > have seen a Atmel to bulk erase itself because the reset line was >> > in 2 meter long cable parallel to wire carrying 12V (reed relay >> > switched) >> > (well Atmel claimed such bulk erase is impossible... >> > but it happened twice and second time i had another >> > guy to witness it, so i wasnt seeing ghosts) >> >> A little off-topic perhaps, but now i'm curious. What atmel chip did >> you experience this erase with? We have just experienced a few >> spontanious erases (over a couple of months) of the first sector of an >> atmel dataflash on one of our boards. Another board in the same system >> uses a dataflash for MCU code and one for FPGA configuration and we have >> not had trouble with those. >> >> -- >> Stef � �(remove caps, dashes and .invalid from e-mail address to reply by mail) >> >> New York's got the ways and means; >> Just won't let you be. >> � � � � � � � � -- The Grateful Dead > > > it was the VERY first samples of ATmega32 > > those samples had m32 written with pencil on top > > no i am lying, it was atmega163 and we tried to program those m32 > > the erasure did erase ALL memory, application sector and boot sector > at same time, and there is no IAP command todo that.. so it should > never happenOK, thanks for the info. No obvious relation to our problem, we keep searching. -- Stef (remove caps, dashes and .invalid from e-mail address to reply by mail) A programming language is low level when its programs require attention to the irrelevant.
Reply by ●March 12, 20092009-03-12
>was just thinking of extending SPI like comms using cheapest >and ready made cabling > >so one pair in each direction only. was hoping to get 50mbit/s?How far do you want to go? Ethernet gets a gigabit in each direction over 4 pairs. That takes a lot of DSP magic and 3 level signaling. Part of the complication is to reduce EMI. Ethernet uses transformers rather than capacitors. I'm not sure why. You should also consider USB. If you are using caps (or transformers) you have to do something to make sure there are no long strings of 0s or 1. Manchester encoding does that at the cost of 2x in bandwidth. (which may not be a problem for short distances) 4b5b, 8b/10b type encoders get back most of the bandwidth at the cost of some complexity at each end. Manchester is trivial to encode and pretty easy to decode with a small state machine if you have a 8x clock at the receiver. -- These are my opinions, not necessarily my employer's. I hate spam.
