R7 (program counter)
E697037
R7 (program counter) is the PDP-11 CPU register that automatically tracks the address of the next instruction to be executed, effectively serving as the machine’s program counter.
Statements (35)
| Predicate | Object |
|---|---|
| instanceOf |
CPU register
ⓘ
program counter ⓘ |
| addressingModeRole |
serves as base for PC-relative addressing
ⓘ
supports immediate addressing via PC-relative modes ⓘ |
| addressSpace | PDP-11 memory address space NERFINISHED ⓘ |
| alsoKnownAs |
PC
ⓘ
program counter ⓘ |
| architecture | PDP-11 NERFINISHED ⓘ |
| autoIncrements | on instruction fetch ⓘ |
| belongsToFamily | DEC PDP-11 NERFINISHED ⓘ |
| canBeModifiedBy |
branch instructions
ⓘ
jump instructions ⓘ return instructions ⓘ subroutine call instructions ⓘ |
| category | computer architecture concept ⓘ |
| dataType | memory address ⓘ |
| function | holds the address of the next instruction to be executed ⓘ |
| influences | execution flow of PDP-11 programs ⓘ |
| introducedIn | early 1970s ⓘ |
| isGeneralPurposeIn | PDP-11 programmer’s model of 8 registers ⓘ |
| manufacturer | Digital Equipment Corporation NERFINISHED ⓘ |
| partOf |
PDP-11 CPU
NERFINISHED
ⓘ
PDP-11 register set NERFINISHED ⓘ |
| readableBy | PDP-11 software via register access ⓘ |
| registerNumber | 7 ⓘ |
| resetBehavior | loaded with start address on reset or boot ⓘ |
| specialRole | dedicated to program counter function ⓘ |
| tracks | address of the next instruction ⓘ |
| updatedOn | every instruction fetch ⓘ |
| usedBy | PDP-11 instruction decoder ⓘ |
| usedFor |
control flow
ⓘ
instruction sequencing ⓘ |
| usedIn | instruction fetch stage ⓘ |
| width | 16 bits ⓘ |
| writableBy | PDP-11 software via control-flow instructions ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.