RCA Spectra 70 - Page 77

5
2
2
Reset PCI Flog
in the Command
Set Program Control
Interrupt Bit in Chonnel
Status Byte
Fetch Data Byte from
Memory
and Send it
to the Device
.... See Note"
10
Yes
I/O S ... vi ce Reque.t
Is Specified Channel
the Multiplexor?
No
Is the PCI Flag in
the Command Set?
r-----------------~No
5
No
6
Yes
7
Has Device Indicated
an End Condition?
No
Decrement the Byte
Count by One
Is the Command
A
Read
Yes
Is the Skip Flag
in the Command Set?
No
Is the Command
a
Sense
Yes
Input/Output Operation
Get Devi ce Addre .. and
Fetch Subchannel
Registe,.
I/O Service Request for
- Multiplexor in Burst Mode
Yes Go to "End and
t--';...;;;..;;;......----. .. Chaining Servicing" - Block 1
Figure 9. Functional Logic of Servicing a Data Transfer
68
.. See to