18 Dec
2016
18 Dec
'16
1:50 a.m.
On Sat, Dec 17, 2016 at 2:59 PM, Chuck Guzis <cclist at sydex.com> wrote:
What perplexed me is that the address of 0000 0 0
specified the first
bit in byte 0 of word 0, but that same bit was the *high order* bit in
the corresponding byte and word. It would seem to make more sense
reversing the significance of bits in a byte and bytes in a word such
that the lowest-numbered addresses corresponded to the least-significant
bits in a word or byte.
Call it "extreme little endianess". Does anyone know of such an
architecture?
The IBM 7030 "Stretch" was bit-addressable for integer operations, but not
for floating point or instructions. It used typical IBM big-endian bit
numbering, with bit 0 being the most significant bit.
The TI TMS34010 and TMS34020 graphics processors were bit-addressable,
though instructions had to be 16-bit aligned. The TMS34010 and the default
mode of the TMS34020 were little-endian, with bit 0 being the least
significant bit. The TMS34020 has configurable support for big-endian
memory addressing.