User`s guide

NVR
Nonvolatile random access memory. A memory device that retains information
in the absence of power.
NVRAM
Nonvolatile RAM. On the KA52/53, this is 1 Kb of battery backed-up RAM on
the SSC.
PC
Program Counter or R15.
PCB
Process Control Block is a data structure pointed to by the PR$_PCBB register
and contains the current process’ hardware context.
PFN
Page Frame Number is an index of a page (512 bytes) of local memory. A PFN
is derived from the bit field <23:09> of a physical address.
PR$_ICC
Interval Clock Control and Status, IPR 24.
PR$_IPL
Interrupt Priority Level, IPR 18.
PR$_MAPEN
Memory Management Mapping Enable, IPR 56.
PR$_PCBB
Process Control Block Base register, IPR 16.
PR$_RXCS
R(X)eceive Console Status, IPR 32.
PR$_RXDB
R(X)eceive Data Buffer, IPR 33.
PR$_SAVISP
SAVed Interrupt Stack Pointer, IPR 41.
Glossary–5