On Jan 9, 11:36, Frank Arnold wrote:
> I wonder, EIS/FIS chip as well as CIS are basicalley Roms that expand the
> microcode control store of the F-11 microprocessor. True?
Almost. They are ROMs, but EIS/FIS is for the 11/03 KD11 processor, not
the F-11 family. CIS is a set of microcode ROMs for the F-11.
There's quite a lot of information in the KDF11 CPU Module User Guide, and
probably more in a technical manual. Basically, it seems that the the
microcode is stored in a device with two bidirectional 16-bit busses (MIB
and CDAL). MIB is a multiplexed bus. Part of the time it outputs the
current microinstruction and the rest of the time it receives control
signals from the CPU. The CDAL bus (which is actually a 22-bit bus, but
only 16 bits are presented to the option sockets) is what eventually
connects to the external BDAL bus, but it's also used internally for
control signals.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Thu Jan 09 2003 - 12:58:00 GMT