Hondata ROMS: What is the minimum latency for the EEPROMs?
10-30-2003, 02:28 PM
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Hondata ROMS: What is the minimum latency for the EEPROMs?
I don't remember the latency on the stock chip, but I'm looking to purchase some and see latencies all over the board, from high of 250 ns all the way down to 70 ns. Does anyone know if there is a minimum or if certain faster ones won't work?
Thanks in advance...
Thanks in advance...
10-30-2003, 04:57 PM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (Willis)
200ns. Well, that is the honda spec, I don't think there should be any special considerations for hondata.
-PHiZ
-PHiZ
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10-30-2003, 08:07 PM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (lazerus)
Well, I use UV-erasable eproms (cause I go through a lot of chips), and just recycle them.
I could imagine the UV-eproms being a little slower than the eeproms. So maybe 70-90ns is the norm with those, but with the UV-eproms, we need to be careful not to get nayhitn >200ns.
-PHiZ
I could imagine the UV-eproms being a little slower than the eeproms. So maybe 70-90ns is the norm with those, but with the UV-eproms, we need to be careful not to get nayhitn >200ns.
-PHiZ
10-30-2003, 11:06 PM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (Willis)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willis »</TD></TR><TR><TD CLASS="quote">170ns or faster.</TD></TR></TABLE>
Stalking me, are you?
I've gotten some 200 ns chips to work, but I think that is because it is cheaper to make a big run of a certain speed ships and them label them however you please to offer a selection at various prices. I have had a LOT of 200 ns chips CEL 0. I don't trust them until I test them.
170 ns or faster, that is what the windowed 27C256 I've pulled out of factory chipped Honduh ECUs are labelled.
Stalking me, are you?
I've gotten some 200 ns chips to work, but I think that is because it is cheaper to make a big run of a certain speed ships and them label them however you please to offer a selection at various prices. I have had a LOT of 200 ns chips CEL 0. I don't trust them until I test them.
170 ns or faster, that is what the windowed 27C256 I've pulled out of factory chipped Honduh ECUs are labelled.
10-31-2003, 09:08 AM
#11
What is this crap?
Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (J. Davis)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis »</TD></TR><TR><TD CLASS="quote">
170 ns or faster, that is what the windowed 27C256 I've pulled out of factory chipped Honduh ECUs are labelled.</TD></TR></TABLE>
so 170ns or faster chips will work cause they will meet the setup and hold times of the bus interface with the 66k processor.
170 ns or faster, that is what the windowed 27C256 I've pulled out of factory chipped Honduh ECUs are labelled.</TD></TR></TABLE>
so 170ns or faster chips will work cause they will meet the setup and hold times of the bus interface with the 66k processor.
10-31-2003, 11:17 AM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (leed)
so some of you guys are using the 27C256 UV-eraseable chips instead of the 29C256 electrically eraseable? Has anyone used the 28C256 EEPROMs? Are they compatible as well?
10-31-2003, 11:27 AM
#14
What is this crap?
Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (leed)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by leed »</TD></TR><TR><TD CLASS="quote">Holy latency.....
Mine are stamped -25dc Is than 25ns or 250ns?
</TD></TR></TABLE>
this probably doesnt have to do with the latency. maybe package / lot information?
Mine are stamped -25dc Is than 25ns or 250ns?
</TD></TR></TABLE>
this probably doesnt have to do with the latency. maybe package / lot information?
10-31-2003, 11:39 AM
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anyone know of places in the Los Angeles area where I can buy these things? I've checked some of the electronics parts supply places around here and no one stocks them, and special order is minimum of 25 units. Maybe a Hondata tuner that can sell me some?
10-31-2003, 11:55 AM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (leed)
They are probably "rated" for 250 ns. The same production lot was probably also stamped -12, -15, -20, as it's cheaper to tool up and produce one size fits all and then sell them on a sliding scale according to "what they are".
As far as 28-series chips, the pinout is different from 27- and 29-series. Not a plug and play chip.
As far as 28-series chips, the pinout is different from 27- and 29-series. Not a plug and play chip.
10-31-2003, 12:48 PM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (J. Davis)
Jameco.com is in belmont CA, I don't know where you are in relation to that, but they offer a local pickup option.
-PHiZ
-PHiZ
10-31-2003, 12:52 PM
#19
What is this crap?
Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (PHiZ)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PHiZ »</TD></TR><TR><TD CLASS="quote">Jameco.com is in belmont CA, I don't know where you are in relation to that, but they offer a local pickup option.
-PHiZ</TD></TR></TABLE>
i just ordered a pile of parts from them. 100 resistors for 99 cents! ack i only needed 3
-PHiZ</TD></TR></TABLE>
i just ordered a pile of parts from them. 100 resistors for 99 cents! ack i only needed 3
10-31-2003, 03:14 PM
#20
Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (roadrunner)
Someone school my newb *** on what latency is in these chips? The units of ns seems to be nano-seconds which would indicate either how fast the binary information is processed or something to that effect. Wish i would have double major in EE/ME..
10-31-2003, 07:13 PM
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Re: Hondata ROMS: What is the minimum latency for the EEPROMs? (boosted hybrid)
FalconGSR, I had resistors.. hehehe.
Boosted hybrid.
It's the same as any model involving latency Vs. throughput, youre' an ME?
Throughput is like how much data you can push. like a T-1 is 1.5Mb/sec.
But how quickly can it respond to a request? On 56k, ever heard of ppl complaining of "lag"
I think someone could make a 1320 analogy of "quickest" driver vs. "fastest" driver, dunno.
-PHiZ
-PHiZ
Modified by PHiZ at 11:28 PM 10/31/2003
Boosted hybrid.
It's the same as any model involving latency Vs. throughput, youre' an ME?
Throughput is like how much data you can push. like a T-1 is 1.5Mb/sec.
But how quickly can it respond to a request? On 56k, ever heard of ppl complaining of "lag"
I think someone could make a 1320 analogy of "quickest" driver vs. "fastest" driver, dunno.
-PHiZ
-PHiZ
Modified by PHiZ at 11:28 PM 10/31/2003
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