6 Sep
2010
6 Sep
'10
4:13 p.m.
On 09/06/2010 02:34 PM, Brent Hilpert wrote:
On 2010 Sep 6, at 5:56 AM, allison wrote:
Many of the 4bit MCUs did that. The instruction set is is similar to
8080 and different since it has
skip on condition and typical Harvard oddities and additions for tables
and inline constants.
The family closest to it is the 1980s ucom75.
Allison
On 09/05/2010 10:06 PM, Brent Hilpert wrote:
> I just ran across an NEC D75008 microcontroller in a small photo
> copier ca. 1990. According to a search it is a 4-bit microcontroller.
>
> Idle curiousity, but does anybody know if this has any inheritance
> from or relation to better-known microcontrollers such as the
> TMS1000, that is, is it NEC's version of something better known?, or
> is it NEC's own architecture?
No, it is NEC unique. For 4 bitters that is
usually the case. it
is a much more expanded
design closer to modern PICs with many variants having LCD driver on
board.
OK, a family I had never run across before. Found a datasheet for (by
appearance) a descendant (D75112/6). Looks like they took a cue from
the 8080 family - the register set is nearly identical but in 4 bits,
with register pairs BC, DE, HL to make 8-bit registers.