I am working with consumer appliances, (convection ovens, breadmakers,
wafflemakers, blenders, and the like) and we are considering using
microcontrollers in some products where steadily dropping silicon costs
have
made it possible to put a small micro where no micro has gone before ;)
. The
cost of OEM quantities of small micros have come down to the point that
my
boss is even considering the dreaded talking toaster application. (See
Circuit Cellar and Steve Ciarcia for a rave against talking toasters - I
can't
remember which issue but it was hilarious)
My question is this - which line of microcontrollers offers the cheapest,
down
and dirtiest brain in large quantities. I don't care how slow, how
little
RAM, how few output pins, how feeble an instruction set, I am interested
mostly in cheap. The applications I am considering for this brain are
very simple, slow, and could probably be done with a handful of logic
chips,
but why bother if ONE chip will do? I am familiar with the PIC series of
course, and if you are buying a truckload of PIC 16C54's, mask
programmed,
they can get pretty low priced, $1.50 to $2.00 US, maybe less. Is there
a
$0.50 cent microcontroller out there?
The old standard from Intel, the 8051, must have some pretty cheap
cousins
by now, Motorola's HC05 series, I have heard, is very inexpensive, and
National has a COP8 and COP4 that I know nothing about except the COP4 is
a 4
bit machine. I didn't know they even MADE 4 bit machines anymore. I
suppose
this would be a cheap chip but it may be phased out any day, no?
I am sure some others in this group have been all through this excercise
before. Thank you in advance for saving me a lot of legwork.
Lawrence O. Lile wrote:
> My question is this - which line of microcontrollers offers the cheapest,
> down
> and dirtiest brain in large quantities. I don't care how slow,
how........snip.......
> but why bother if ONE chip will do? I am familiar with the PIC series of
> course, and if you are buying a truckload of PIC 16C54's, mask
> programmed,
> they can get pretty low priced, $1.50 to $2.00 US, maybe less. Is there
> a
> $0.50 cent microcontroller out there?
The closest thing I'm aware of is Zilog's lowest end Z8 part. Last I heard,
these could be had for about $0.67 in 50K quantities. The cheapest masked
version of the 16C54 was next in line at somewhere around $0.95 in similar
quantities. The lowest Z8's features have a few disadvantages, as well as
a few advantages over the lowest PIC's. But overall, they offer a level of
capability comparable to their PIC counterparts.
> My question is this - which line of microcontrollers offers the
> cheapest, down and dirtiest brain in large quantities. I don't
> care how slow, how little RAM, how few output pins, how feeble an
> instruction set, I am interested mostly in cheap. .... I am
> familiar with the PIC series of course, and if you are buying a
> truckload of PIC 16C54's, mask programmed, they can get pretty low
> priced, $1.50 to $2.00 US, maybe less.
Yes, and in quantity, the 16CR5x masked chips are only
marginally cheaper than the regular 16C5x chips.
> Is there a $0.50 cent microcontroller out there?
Yes.
> The old standard from Intel, the 8051, must have some pretty cheap
> cousins by now
Nope.
> Motorola's HC05 series, I have heard, is very inexpensive
Not THAT inexpensive, and their availability sucks.
> National has a COP8 and COP4 that I know nothing about except the
> COP4 is a 4 bit machine. I didn't know they even MADE 4 bit
> machines anymore. I suppose this would be a cheap chip but it may
> be phased out any day, no?
Maybe, but it's probably the only micro you'll find in the
50-cent range. To get that price, of course, you need to be
doing serious quantities... Like 500K and up.
You'll really love programming the COP400... Its ROM is
organized into 64-byte pages, its RAM is organized into multiple
pages of eight 4-bit registers, its assembly language uses
mnemonics even worse than the PIC's (CAMQ, LQID, STII, XAD, XDS,
etc.), and most instructions have multiple (usually undesirable)
side-effects. For instance, the X instruction (yes, just "X")
exchanges the contents of the Accumulator and the register
pointed to by the "B" RAM Address Register, then exclusive-ORs
the upper two bits of the B register with a single bit specified
by the operand of the X instruction.
Additionally, some instructions may only be used on certain ROM
pages, and others behave differently depending upon the page
they're on. JP, for instance, can be used to jump to any
location within the current page UNLESS you're on subroutine
page 2 or 3, in which case it can be used to jump to any
location in EITHER of those pages. It can NEVER be used to jump
to the last location on any page.
JSRP jumps to a location on subroutine page 2, but it may not be
used FROM page 2 or 3. It also may not be used to jump to the
last location on page 2.
Oh, wait... Here's one you'll like. I'll copy the description
directly from the data sheet:
INIL Instruction
INIL (Input IL Latches to A) inputs 2 latches, IL3 and IL0,
CKO and 0 into A. The IL3 and IL0 latches are set if a
low-going pulse ("1" to "0") has occurred on the IN3 and IN0
inputs since the last INIL instruction, provided the input
pulse stays low for at least two instruction cycles.
Execution of an INIL inputs IL3 and IL0 into A3 and A0
respectively, and resets these latches to allow them to
respond to subsequent low-going pulses on the IN3 and IN0
lines. If CKO is mask programmed as a general purpose
input, an INIL will input the state of CKO into A2. If CKO
has not been so programmed, a "1" will be placed in A2. A0
is input into A1. IL latches are cleared on reset.
Fun stuff.
Of course, National goes out of their way to make development
easy... For a couple thousand dollars, you can buy a MOLE
emulator that uses not just ANY 1970's-era technology, but
technology from the LATE 70's.
[snip]
>> the dreaded talking toaster application.
>>
[snip]
>> My question is this - which line of microcontrollers offers the cheapest,
[snip]
>>
>> Lawrence Lile
>>
Let us know what you find out... who knows, it may be cheaper to use
a lot of processors than to buy RAM to store data in! :)
MITVMA.MIT.EDU> wrote:
