Advertisement
Figure 3-18.
ROS Storage Control Fields
In the 2030 there are four basic
cycles for core storage.
Read, Write
(R,
W)
Read, Compute, Write CR, C, w)
Read, Store CR, S)
Read, Compute, Store (R, C, S)
When a read call is given, the data
from core storage is not ready for use
until the beginning of the next ROS
cycle.
The next cycle then must be a
write, a store, or a compute cycle.
If the read cycle is followed by a
write cycle, the data will be set in the
storage data register
(R)
and sent back
to core from R.If followed by a store
cycle the output from core is not used
but lost.
The new informa·tion for core
is the data already in R, and this is
gated back to core.
If the read cycle is followed bya
compute cycle, the output from core is
taken to R and must be written back to
core on the cycle following the compute
cycle with either a write or store.
READ, WRITE
(CM):
The 3-bit CM field
controls the operation to
be
performed.
A read call is sent to core storage
.
using one of the CM field combinations 3
through 7.
A write call is specified by
the codings 0 or 2.
Note: If the CM field is combination
000
~rite),
001, or 010 (Store), the
alternate coding for CU is used.
A 001
3-19
Advertisement
