Register - Revision history

Jnc: Register renaming

2021-05-14T11:10:35Z

Jnc: +cat

2018-12-13T02:39:26Z

+cat

Jnc: Proper cat, clarify a bit

2018-10-20T20:37:48Z

Proper cat, clarify a bit

Jnc: rm plural from link

2018-04-27T13:13:17Z

rm plural from link

Jnc: Add links

2018-04-27T13:10:44Z

Add links

Jnc: typo

2017-09-21T19:34:14Z

typo

Jnc: avoid redir

2017-09-21T19:32:05Z

avoid redir

Jnc: add mention of accumulator

2017-09-21T16:28:31Z

add mention of accumulator

Jnc: Stubby, but a start

2017-09-16T21:13:54Z

Stubby, but a start

New page

A '''register''' is a special storage location; usually within a [[CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.

The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and bits in the instruction word are (and always will be) a limited resource.

==See also==

* [[Stack Pointer]]
* [[Program Counter]]

{{stub}}

@@ Line 3: / Line 3: @@
 The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scarce resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].
-Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and [[bit]]s in the instruction [[word]] are (and always will be) a limited resource.
+Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of programmer-visible registers, because they are named by fields in [[instruction]]s, and [[bit]]s in the instruction [[word]] are (and always will be) a limited resource. ([[Register renaming]] was developed to allow more registers to be used, without being able to explicitly name them.)
 ==See also==

← Older revision		Revision as of 02:39, 13 December 2018
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	{{semi-stub}}		{{semi-stub}}
		+
		+	[[Category:Hardware Basics]]

@@ Line 1: / Line 1: @@
-A '''register''' is a special storage location; usually within a [[Central Processing Unit|CPU]], i.e. not part of the machine's [[main memory]], although [[device controller]]s usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.
+A '''register''' is a special small [[memory]] unit; usually within a [[Central Processing Unit|CPU]], i.e. not part of the machine's [[main memory]], although [[device controller]]s usually include registers too. For the ones which are part of the CPU, access to them is very fast - usually faster than main memory.
-The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].
+The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scarce resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].
-Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and bits in the instruction [[word]] are (and always will be) a limited resource.
+Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and [[bit]]s in the instruction [[word]] are (and always will be) a limited resource.
 ==See also==
@@ Line 10: / Line 10: @@
 * [[Program Counter]]
-{{stub}}
+{{semi-stub}}

← Older revision		Revision as of 13:13, 27 April 2018
Line 1:		Line 1:
−	A '''register''' is a special storage location; usually within a [[Central Processing Unit\|CPU]], i.e. not part of the machine's [[main memory]], although [[device ~~controllers~~]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.	+	A '''register''' is a special storage location; usually within a [[Central Processing Unit\|CPU]], i.e. not part of the machine's [[main memory]], although [[device controller]]s usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.

	The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].		The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].

@@ Line 1: / Line 1: @@
 A '''register''' is a special storage location; usually within a [[Central Processing Unit|CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.
-The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].
+The first computers did not include many registers in the CPU, since each register needs separate [[hardware]], and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].
-Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and bits in the instruction word are (and always will be) a limited resource.
+Later on, hardware was not so much of an issue, but computers still tend to have somewhat limited numbers of registers, because they are named by fields in [[instruction]]s, and bits in the instruction [[word]] are (and always will be) a limited resource.
 ==See also==

← Older revision		Revision as of 19:34, 21 September 2017
Line 1:		Line 1:
−	A '''register''' is a special storage location; usually within a [[Central ~~Crocessing~~ Unit\|CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.	+	A '''register''' is a special storage location; usually within a [[Central Processing Unit\|CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.

	The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].		The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].

← Older revision		Revision as of 19:32, 21 September 2017
Line 1:		Line 1:
−	A '''register''' is a special storage location; usually within a [[CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.	+	A '''register''' is a special storage location; usually within a [[Central Crocessing Unit\|CPU]], i.e. not part of the machine's [[main memory]], although [[device controllers]] usually include registers too. Since they are part of the CPU, access to them is very fast - usually faster than main memory.

	The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].		The first computers did not include many registers in the CPU, since each register needs separate hardware, and that was a scare resource early on. Many machines only had a single register available for doing computations with, the '''accumulator'''; these machines were typically a [[load-store architecture]].