I wrote:
> The 68000 has three separate 16 bit ALUs: one for DataLow, one for
> AddressLow and another for AdressHigh. DataHigh can be processed by
> either the first or the second one. The first one implements all
> operations while the other two only do add/subtract and some limited
> shifting.
> See figure 8 of:
> https://www.computer.org/csdl/mags/co/1979/02/01658617.pdf

Ooops- my explanation got the last two ALUs backwards. DataHigh and
AddressHigh share an ALU.

Note that in the conclusion to this 1979 article, the Motorola engineers
say "It is a 32-bit architecture that supports many data types and data

- Jecel.

Reply via email to