Cray CRAY-1 - CRAY-1 Monitor Functions (001 xxx)

001 i j k
Monitor functions
I This instruction is privileged to monitor mode and performs specialized
functions useful to the operating system. Functions are selected through
the i
designator. The instruction is treated as a pass instruction if the
monitor
mode bit is not set or if the i designator is 5, 6, or 7.
Subfunctions defined
by the i designator are as follows:
OOlOjk
0011j k
0012jx
5et the current address (CA) register for the channel
inc!icated
by (Aj) to (Ak) and activate the channel
Set the limit address (CL) register for the channel
indicated by (Aj) to (Ak)
Clear the interrupt flag and error flag for the
0013jx
0014jx
channel indicated by (Aj) and/or deactivate the channel
Enter the
XA register with (Aj)
Enter the
real-time clock register with (Sj)
When the i designator is 0, 1, or 2, the instruction controls the
operation
of the I/O channels. Each channel has two registers that
direct the channel activity. The CA register for a channel contains
the address of the
current channel word. The CL register specifies
the limit address. In programming the channel, the CL register is
initialized and setting CA activates the channel. As the transfer
continues, CA is incremented toward CL. When (CA) = (CL), the
transfer is complete for words at initial (CA) through (CL)~l.
When the j designator is 0 or when the content of Aj is less than 2
or
greater than 25, the functions are executed as pass instructions.
When the k designator is 0, CA or CL is set to 1.
When the i designator is 3, the instruction transmits bits 211 through
24 of (Aj) to the exchange address (XA) register. When the j designator
is 0, the XA register is cleared.
2240004
4-8
E