john@anasaz.UUCP (John Moore) (03/02/90)
I am looking for a microcomputer chip with the following characteristics.
If you know of such a beast, please email.
(1) On board EPROM or EEPROM, or built in piggyback socket for same,
of at least 4K Bytes - preferrably 8K.
(2) On board RAM of at least 256 Bytes.
(3) Built in multiply and divide - preferrably 16 bit.
(4) 16 bit accumulator and math.
(5) On-chip A/D - at least 8 bits, at most 40uSec conversion time,
with Sample and Hold. This is optional but desirable.
(6) Price less than $30.00 in small quantities
(7) On chip interrupting timer - programmable interval.
Thanks...
--
John Moore (NJ7E) mcdphx!anasaz!john asuvax!anasaz!john
(602) 951-9326 (day or eve) long palladium, short petroleum
7525 Clearwater Pkwy, Scottsdale, AZ 85253
Support ALL of the bill of rights, INCLUDING the 2nd amendment!chuck@mitlns.mit.edu (03/03/90)
-Message-Text-Follows- In article <1365@anasaz.UUCP>, john@anasaz.UUCP (John Moore) writes... >I am looking for a microcomputer chip with the following characteristics. >If you know of such a beast, please email. > (1) On board EPROM or EEPROM, or built in piggyback socket for same, > of at least 4K Bytes - preferrably 8K. > (2) On board RAM of at least 256 Bytes. > (3) Built in multiply and divide - preferrably 16 bit. > (4) 16 bit accumulator and math. > (5) On-chip A/D - at least 8 bits, at most 40uSec conversion time, > with Sample and Hold. This is optional but desirable. > (6) Price less than $30.00 in small quantities > (7) On chip interrupting timer - programmable interval. > > What you want exists but I haven't found it for <$30 more like $75 and up. Hitachi is one source and INTEL is another that have piggyback versions of their processors. I would suggest however, that you use the Motorola 68HC11A2 available off the shelf in quantity 1 for $18.00 from Active Electronics. You will need to add a 74HC573 address latch and an external EPROM. Active has 27C128's for $4.25 quantity one. To do things right you need 1 or 2 inverters. Invert R/W and send it to the output enable on the CHIP, that is all you have to do. You will get lower power if you also NAND A15 and E and use that as a chip select. I know that is some wiring, but not a lot. The advantages are you have some one who will sell you just one and low cost, and its off the shelf. The chip has everything you want. 256 bytes RAM A/D 8 channels multiplexed 16us conversion time built in sampe/hold It has a high input impedence you can drive it with 10K ohms If you don't multiplex channels (charge sharing occurs then) you can use >100k if the signal is not to quickly varying Very flexible timer interrupt 5 timer controlled outputs 3 time latched inputs About a dozen different possible timer interupts Built in 8x8 to 16 bit multiply (5 cycles) Built in 16/16 to 32 bit divide instruction (41 cycles) Built in Serial port, great for talking to your PC... 512 bytes EEPROM The 68HC11E2 has 2kEEprom and can be run as in single chip mode. It is in your price range if you could squeeze in to that much memory. Bad news is availabilty is not that good it just took 3months for us to get 3. The 68HC11F1 has 1k RAM a non multiplexed bus and internal chip select logic so you wouldn't need ANY glue. It also accepts a higher clock speed of 4 MHZ. Since the A/D runs off the clock that should give you a 8us conversion but I haven't checked the specs. I'm sure availabilty on this is not so good either You should expect about 20ma to power everything at 1-2Mhz if you use a CMOS eprom. Active Electronics has Stores in Westborough and Worburn Mass. You can call information to get their number they will send you a catalogue. They are one of the very few places willing to deal with the hobbiest. Standard electronics places have hundred dollar minimums often will want to do a credit check and generally won't want to deal with you if you aren't a company or university. Places like Jameco or JDR are fine if they stock what you want but their selection is not as good as Active and they won't order small quantities for you. Chuck Parsons CHUCK@MITLNS.MIT.EDU CHUCK@MITLNS.BITNET
john@anasaz.UUCP (John Moore) (03/04/90)
In article <1990Mar2.162646.22586@athena.mit.edu> chuck@mitlns.mit.edu writes:
Thanks for the info. I will look more closely at the 68HC11 series. However,
avoiding the off-chip ROM and RAM is my main interest. There is a nice Intel
chip series (8097, etc) that I have used where off-chip EPROM is acceptable -
about $9.50 with all the features of the HC11 + 10 bit A/d but no EEPROM.
]Standard electronics places have hundred dollar minimums often will
]want to do a credit check and generally won't want to deal with you
]if you aren't a company or university. Places like Jameco or JDR are
I have a (very) small side business that manufactures ham radio
computerized widgets. I have accounts with many distributors
(such as Hamilton/Avnet). Most of them will accept orders of any
size - they make sure they make money by having large ($5.00) handling
charges. It's not hard to get these accounts, by the way. Also,
Arrow electronics now has an outlet that has a nationwide 800
number (1-800-93ARROW) that will take Visa cards and has the stock
(but not quite the prices) of a distributor.
--
John Moore (NJ7E) mcdphx!anasaz!john asuvax!anasaz!john
(602) 951-9326 (day or eve) long palladium, short petroleum
7525 Clearwater Pkwy, Scottsdale, AZ 85253
Support ALL of the bill of rights, INCLUDING the 2nd amendment!