From: email@example.com (S. Marget MacLeod - Silberstein)
Subject: Re: ? Binary to BCD conversion chip ?
Date: 5 Dec 2002 19:53:03 -0800
NNTP-Posting-Date: 6 Dec 2002 03:53:03 GMT
"Roger Hamlett" wrote in message news:...
> "Yi-Zen Chu; Yiren Qu" <""y i z e n \"@ u c l i n k 4 . b e r k e l e y . e
> d u> wrote in message news:mUeF9.151366$NH2.11112@sccrnsc01...
> > Hello everyone,
> > Does anyone know if there's any IC chip commercially available that can
> > convert a 4 (or 8 bit) number to BCD? Where can I buy it? I tried
> > looking up on the Net but only found 74185, which seemed to be
> > Thanks for the help!
> Others have allready suggested using an EPROM, but it is also worth asking
> what sort of speed is required, and whether there are any other functions
> that need to be done?. One reason these chips have disappeared, is that this
> sort of decoding can be done so easily in a microprocessor now, and in many
> cases with less power consumption. For example, the same logic as the 74185,
> could be generated in a basic PIC, that in the UK, costs about £1.50 in one
> off quantities. Using it's own internal oscillator (so no need for a
> crystal), the conversion could be coded in about half a dozen instructions
> (using a look up table), giving a latency of perhaps 10uSec. This sort of
> chip, consumes uA, so provided the speed requirement is slow, could well be
> an economic solution. If the total conversion required is more complex
> (perhaps feeding seven segment displays), this type of choice becomes even
> better, since a slightly larger chip could be programmed to directly drive
> the digit segments, removing the need for a seperate BCD to seven segment
> converter. I also have to ask where the binary patterns are coming from?. In
> many cases, applications that used this type of chip in the past, can now be
> done using other products, that give BCD directly.
> You mention coding just 4 or 8 bits 'sections', which is very easy to do in
> a 'look up table' solution (this is the EPROM that has allready been
> suggested), the only problem with this solution, is finding small ROMs these
> Best Wishes
I have a related question: Does anyone kow of a good way to convert 12
bit binary to bcd? This comes after a 12 bit ripple counter that will
count to 4096 in one second.