RCA 70/46 Reference Manual page 83

2
Tell Device Control
Electronics to Set an End
Condition when Device is
No Longer Busy
Input/Output Operation
From Servicing a Data Transf.r
and Device Control Electronics has Indicated an End Condition
2
Ves
3
Receive the Standard
Device Byt. from Device
Control Electronics
Does the Standard Device
Byte Indicate a Device
Busy Condition?
No
~~
__
A8~==========:j(N~0=rm=a=I==E=n=d=s=e~r~v_iC_i~ng)
No
Is the Chain Command
(CC) Flag Set?
9
No
9
See Note 3)
Tell Device Control
Electronics to Set Channel
Interrupt
Is This a Multiplexor
Channel Device?
Ves
Store Subchannel Registers
Back in Non-Addressable
Main Memory
Next Instruction
..
Ves
S
Ves
6
No
7
Ves
Test Channel Status Byte
for: Program Check, Pro-
tection Check, Data Check
or Channel Control Check
No
Is the Chain Data
(CD) Flag Set?
No
Test Standard Device
Byte for the Following:
• Device Inoperable = No
• Secondary Ind = No
• Device End = Ves
Ves
I s Byte Count i
o
and SLI Flag =
0
These Tests are made to see if Command Chaining
can take place. Failure of any of these Tests
causes Command Chaining to be Suppressed
Figure 10. Functional Logic of End and Chaining Servicing
74