R6 and R7 are used in a special way by the CPU and are referred to in a program by special names. ... The CPU executes instructions using the PC as the address of the next instruction to be fetched from memory. ... The stack is used for storing the information needed to return from a trap or interrupt (or subroutine). ... the Processor Status Register CURRENT MODE PREVIOUS MODE* a GENERAL REGISTER SET (0.11 aiMODE:00 = KERNEL 01=SUPERVISOR 11 = USER Table 5.
|Publisher||:||Digital Pr - 1984-06-01|