Difference between revisions of "Register"
Chris Tyler (talk | contribs) (Created page with 'Category:Computer Architecture{{Chris Tyler Draft}}A register is a high-speed memory location within a CPU. Various types of registers are used in combination in various com…') |
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* '''Status registers''' (or Flag registers, or Condition code registers) contain flag bits, which are set/cleared/tested either explicitly (by instructions) or implicitly (as the result of other operations). For example, the ARM aarch32 "Z" flag is set ("1") if an operation has a non-zero result, and cleared ("0") if an operation has a non-zero result. This flag is one bit within the Application Processor Status Register (APSR). | * '''Status registers''' (or Flag registers, or Condition code registers) contain flag bits, which are set/cleared/tested either explicitly (by instructions) or implicitly (as the result of other operations). For example, the ARM aarch32 "Z" flag is set ("1") if an operation has a non-zero result, and cleared ("0") if an operation has a non-zero result. This flag is one bit within the Application Processor Status Register (APSR). | ||
* '''Control registers''' alter the operation of the processor, such as by enabling binary coded decimal (BCD) math or toggling [[Endian|little-endian/big-endian]] mode. | * '''Control registers''' alter the operation of the processor, such as by enabling binary coded decimal (BCD) math or toggling [[Endian|little-endian/big-endian]] mode. | ||
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+ | The term ''register'' may also be used to refer to an IO port or a memory address within a memory-mapped input/output device, used to set/read device status and parameters. |
Revision as of 20:55, 15 December 2013
Various types of registers are used in combination in various computer architectures:
- General-purpose registers are used to temporarily store values.
- Accumulators hold the results of mathematical operations (originally add/subtracts, but now any numerical operation).
- Status registers (or Flag registers, or Condition code registers) contain flag bits, which are set/cleared/tested either explicitly (by instructions) or implicitly (as the result of other operations). For example, the ARM aarch32 "Z" flag is set ("1") if an operation has a non-zero result, and cleared ("0") if an operation has a non-zero result. This flag is one bit within the Application Processor Status Register (APSR).
- Control registers alter the operation of the processor, such as by enabling binary coded decimal (BCD) math or toggling little-endian/big-endian mode.
The term register may also be used to refer to an IO port or a memory address within a memory-mapped input/output device, used to set/read device status and parameters.