Write Direct, Internal Basic Processor; Control (Mode 0) - Xerox 550 Reference Manual

WRITE DIRECT. INTERNAL BASIC PROCESSOR
CONTROL (MODE 0)
LOAD SE NSE SWITCHES
The following configuration of WDcan be used to load the
sense switches in the System Control Processor:
If the R field is nonzero, bitsOthrough30f RegisterRwill be
loaded into sense switches 1 through 4 in the System Control
Processor. IftheRfield is zero, sense switches will be reset
to zeros. (See the section "SystemControl Panel
II
in Chap-
ter 5. )
SET INTERRU PT INHIBITS
The following configuration of WD can be used to set the
interrupt inhibits (bit positions 37-39 of the PSWs):
A logical inclusive OR is performed between bits 29-31 of the
effective virtual address and bits 37-39 of the PSWs. If any
(or a II) of bits 29-31 of the effecti ve vi rtua I address are l's,
the corresponding inhibit bits in the PSWs are set to 1's; the
currentstate of an inhibit bit is not affected if a correspond-
ing bit position of the effective virtual address contains a O.
Note that a copy of the Interrupt Inhibits is retained in the
Interrupt Status Register in the Processor Interface associated
with each basi c processor.
RESET INTERRUPT INHIBITS
The following configuration of WD can be used to reset the
interrupt inhibits:
If any (or all) of bits 29-31 of the effective virtual address
are 1's; the corresponding inhibit bits in the PSWs are reset
to O's; the current state of an inhibit bit is not affected if
a corresponding bit position of the effective virtual address
contains a O.
Note that a copy of the Interrupt Inhibits is retained in the
Interrupt Status Register in the Processor Interface asso-
ciated with each basic processor.
SET ALARM INDICATOR
The following configuration ofWDis used to set theALARM
indicator on the maintenance section of the processor con-
trol panel:
108 Contro I Instructions
If the processor is in the RUN mode and the AUDIO switch
on the maintenance section of the processor control panel
is in the ON position, a 100o-Hz signal is transmitted to
the basic processor speaker. The signal may be interrupted
by changing from RU N mode to IDLE mode, by moving the
AUDIO switch to the OFF position, or by resetting the
ALARM indicator.
RESET ALARM INDICATOR
The following configuration of WD is used to reset the
ALARM indicator:
The ALARM indicator is also reset by either the RESET BP
or the RESET SYSTEM Command entered from the operator's
contro I conso Ie.
TOGGLE PROGRAM-CONTROLLED-FREQUENCY
FLIP-FLOP
The following configuration ofWD is used to set and reset the
basic processor program-control led-frequency (PCF) flip-flop:
The output of the PCF fli p-flop is transmitted to the basic
processor speaker through the AUDIO switch on the main-
tenance section of the System Control Panel. If the PCF
flip-flop is reset when the above configuration of WD is
executed, the WD instruction sets the PCF flip-flop; if the
PCF flip-flop was previously set, the WD instruction resets
it. A program can thus generate a desired frequency by
setting and resetting the PCF fl ip-flop at the appropriate
rate. Execution of the above configuration of WD also
resets the ALARM i ndi cator •
LOAD INTERRU PT INHIBITS
The following configuration of WD can be used to transfer
the contents of the spec ified R reg ister (R29-31) to the
Interrupt Inhibit fie Id (PSWs
37
_
39
).
Affected: (PSWs
37
_
39
)
(R 29 - 31 ) - PSWs 37 -39
TURN ON MODE ALTERED FLAG
The following configuration of WD is used to set the Mode
Altered Flag (PSWs 61) to 1: