RCA 70/46 Reference Manual page 127

Write Direct
(WRD)
General Description
Format
(SI)
Condition Code
Interrupt Action
Privileged
Instructions
• The eight-bit byte specified by the first address (Bl/Dd is accessed and
transmitted to all units via the Static Out lines. The eight-bit I field
specifies the Signal Out lines to be pulsed. The Static Out lines remain as
specified until the next Write Direct instruction.
84
o
7 8 15 16 19 20
31
• Unchanged.
• Privileged operation.
Address error:
Addressing.
Operation code trap (if Direct Control option is not installed).
Notes
1.
Each trunk has only one Signal Out line and is pulsed according to
the following pattern:
I-Fiel4 Trunk(s) Pulsed
Bit to
=
1 Six
Bit 1
=
1 Five
Bit 2
=
1
Four
Bit 3
=
1
Three
Bit 4
=
1
Two
Bit 5
=
1
One
Bit 6
=
0
Reserved (Must be zero)
Bit 7
=
0
Reserved (Must be zero)
More than one I-Field bit may be set to 1 providing pulses for
sending over more than one direct control trunk. This permits
sending the same byte to all processors connected
to
the trans-
mitting processor.
2. A processor cannot Write Direct to itself. The I-Field bit associated
with the transmitting processor must always be reset to zero. (This
is a programming restriction.)
3. An I field of all zeros causes the byte specified by the first address
to be placed on
aU
trunks but does not cause an interrupt to occur
in the other connected processors. This byte can be read by a Read
Direct instruction.
118