User programmable 4bit micro? Just for fun - Page 1
Forum section: electronics / general

author: ddavidebor
author_rank: Super Contributor
timestamp: July 06, 2013, 12:39:01 pm
content: Hi guys.Do you know if there is any user programmable (assembly obviusly) 4bit microcontroller?Not microprocessor, microcontroller.

author: free_electron
author_rank: Super Contributor
timestamp: July 06, 2013, 01:21:01 pm
content: toshiba hitachi oki mak plenty of thoae. most commonly found in older car radios.they are microcontrollers but are typically mask rom. there are bond out version where you can put an eprom on their back to run code.

author: brainwash
author_rank: Frequent Contributor
timestamp: July 07, 2013, 06:17:24 pm
content: I think also Holtek might still make them, for toys mostly, but it will probably be an exercise in reverse-engineering since AFAIK they don't provide all the details except under NDA and with >1k purchases. This is just what I heard, don't quote me.

author: amyk
author_rank: Super Contributor
timestamp: July 08, 2013, 05:46:52 am
content: Atmel used to make them, look at the T48C series.There's the EM6580 which is Flash:http://www.emmicroelectronic.com/products.asp?IdProduct=215An odd cut-down 8051 derivative (a 4051?) :http://www.coreriver.com/product-lines/CORERIVERmcu_linkATOM11.htmlThe majority of 4-bit micros seem to come from the far East: Epson, Hitachi, NEC (now Renesas), Samsung, Sony, etc. not to mention the countless Chinese manufacturers...I don't think Holtek still make them, or if they do they don't say so on their site.

author: Stonent
author_rank: Super Contributor
timestamp: July 08, 2013, 05:49:59 am
content: I took apart a remote for a Dell TV once, it had a 4 bit Renesas Micro with integrated keypad controller.

author: westfw
author_rank: Super Contributor
timestamp: July 09, 2013, 06:27:12 am
content: I have some Toshiba TMP47P443VN chips. They're an apparently rare one-time-programmable chip; they program like EPROMs (parallel interface, odd voltages, funky algorithms.) I don't know if there ever were any flash, eeprom, or eraseable EPROM 4-bit microcontrollers; as others have said, they were mostly done in mask-programmer versions. There are very limited tools (assemblers from Nth parties, etc), and the instruction set architecture is sort of a cross between a stripped 8080 and the less pleasant 8-bit PIC chips: one AC, one pointer register, a bunch of instructions that operate directly on data memory.The datasheet says:4k * 8 instruction memory256*4 data memory.1 us instruction time at 8MHz.4.2MHz at 2.2V92 instructions, incuding table lookup and 5bit to 8bit conversion instructions15 level subroutine nesting.6 interrupt sources.23 pins of IOInterval Timertwo 12bit timer/counters"Serial" interface8bit A-D with 8inputs and 24us conversion timePulse output (buzzer drive or Remocon carrier.)Zero-Cross detectorI haven't managed to do anything with them yet. I'm not sure I ever will; I'd forgotten how unpleasant things were in the pre-flash-memory days.

author: AlfBaz
author_rank: Super Contributor
timestamp: July 09, 2013, 06:43:48 am
content: Quote from: westfw on July 09, 2013, 06:27:12 amI still remember how excited I got when I received my first UV erasable micro!

author: AlfBaz
author_rank: Super Contributor
timestamp: July 09, 2013, 06:47:07 am
content: Quote from: ddavidebor on July 06, 2013, 12:39:01 pmYou may be able to double or even triple your "fun" and learn something useful in the process.Get an FPGA/CPLD dev board, create your own 4bit micro and program it

author: brainwash
author_rank: Frequent Contributor
timestamp: July 09, 2013, 07:06:36 am
content: http://www.renesas.com/products/mpumcu/720/index.jsphttp://datasheets.chipdb.org/National/COP400/NS_COP400_Family.pdfhttp://en.wikipedia.org/wiki/TLCS-47andhttp://en.wikipedia.org/wiki/4-bithttps://www.nuvoton.com/NuvotonMOSS/Community/ProductInfo.aspx?tp_GUID=8416b88a-0bd8-4173-8ecb-cc30a4a69caahttps://www.nuvoton.com/NuvotonMOSS/Community/ProductInfo.aspx?tp_GUID=2e197b1c-9cdb-4a07-9c3f-27f476247915https://www.nuvoton.com/NuvotonMOSS/Community/ProductInfo.aspx?tp_GUID=11734267-2901-4370-a569-cb8642e92feaSeiko and ST (part of STC series) also have some with LCD controllers.There's a wealth of 4-bit chips in toys, remote controls, recording machines,  house/car alarm systems, watches, simple handheld games, weather stations. I suspect Chinese distributors are the go-to suppliers for these but I doubt any documentation is in  English. Like with those all-in-one ARM dev boards. Toolchains are also hard to get by, you'd spend less time writing directly in machine code than finding one.I second the approach of FPGA and/or software simulation. I also don't see the point very much unless writing FW for a 5M+ market where 1c/part cost makes a noticeable difference.For an easy ride just go with this:http://e4004.szyc.org/

author: ddavidebor
author_rank: Super Contributor
timestamp: July 09, 2013, 08:19:03 am
content: Thank you, interesting!