25 May
2011
25 May
'11
12:27 p.m.
On Wed, 25 May 2011, Tony Duell wrote:
Basically (and this is what the data sheets don't
tell you), it's a
microcontroller. It's a CPU, RAM, ROM (a bootstrap program) and I/O (4
transputer links) on one chip. It's designed for parallel porcesing, you
can either have several processings running on one chip (timesliced, of
course), or on separate chips commuinicating via the links. The software
changes in Occam to go from one to the other are very minor.
I don't know of any transputers with on-chip ROM, which model would that be?
The chip has an external memory bus, and generates the
refresh address for
DRAMs. The meory control signals are configruable. Adding external
memory (even DRAM) or I/O to these devices is very easy, at lerast on the
common T4s and T8s. There's one member of the T8 family (I forget the
number, it's either T801 or T805) that was optimised to use SRAM only and
has a somewaht faster memeory cycle time than the other members of the
family, but I would be surprised if you'd got that one.
The 801 is the SRAM optimised one (separate address and data buses); the
805 is the 800 plus the break instruction and the Event Waiting pin.
Alexey