The Coldire V1's multiplier/accumulator is described as having a multiply/accumulate/load mode to speed up MAC-operations.
It also can implement circular addressing, so that no overhead is incurred for address-checking.
I can't figure out the syntax, however: it seems that one must write:
mac.w D0.L, D1.L, (A0)+& , D0 ;
... in order to
word-multiply D0 and D1,
add their product to the accumulator,
'and' A0's address with the MASK-register,
load the value newly-indicated by A0 into D0
But I cannot have both the '-' and '&' in the line at the same time. This seems odd, as if A0 must be separately incremented OR it must be separately masked.
What have I missed?
As I understand it, you can:
mac.w D0.L, D1.L, -(A0)& , D0
If you look at other CF instructions and addressing modes available, postincrement (Ax)+ and predecrement -(Ax) are available, but not +(Ax) or (Ax)-.
D0 in your list of steps should be loaded with data at (A0 & mask) frist, and only then A0 should be incremented to point to the next data. In -(Ax) case, A0 is first decremented, and then D0 is loaded.