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…') |
Chris Tyler (talk | contribs) |
||
| Line 6: | Line 6: | ||
* '''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. | ||
| + | |||
| + | 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 21:55, 15 December 2013
This is a draft only!
It is still under construction and content may change. Do not rely on this information.
It is still under construction and content may change. Do not rely on this information.
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.
