IOX - Revision history

TArntsen: Typo fix: and -> an

2019-02-01T14:02:43Z

Typo fix: and -> an

← Older revision		Revision as of 14:02, 1 February 2019
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	The actual transfer direction of the IOX and IOXT instructions is decoded from the device-register address, based on the following convention: the transfer direction is input (from device to CPU) if the device-register address is even.		The actual transfer direction of the IOX and IOXT instructions is decoded from the device-register address, based on the following convention: the transfer direction is input (from device to CPU) if the device-register address is even.

	This means that all I/O device registers which need to be loaded from the CPU A register are assigned ~~and~~ odd device register address. Similarly I/O device input registers are assigned even addresses.		This means that all I/O device registers which need to be loaded from the CPU A register are assigned an odd device register address. Similarly I/O device input registers are assigned even addresses.

	== Device register address ==		== Device register address ==

2011-12-20T22:24:36Z

added Address range section

← Older revision		Revision as of 22:24, 20 December 2011
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	* The number of external devices that can be controlled by the CPU depends on the configuration of the devices.		* The number of external devices that can be controlled by the CPU depends on the configuration of the devices.

			== Address range ==
			The IOX instruction can address a total of 2048 registers, i.e. addresses from 0 - 3777 (octal). However, the device-registers implemented on interfaces designed at [[Norsk Data]] use the address area 0 - 1777 (octal) only. The remaining 1024 register addresses are available for customer-designed interfaces.

	== Example ==		== Example ==

2011-12-20T22:18:35Z

Se also: corrected spelling

2011-12-20T22:13:42Z

added Direction of transfer section

← Older revision		Revision as of 22:13, 20 December 2011
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	IOX (the Input/Output Instruction) is a privileged instruction in normal cases, but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external interfaces.		IOX (the Input/Output Instruction) is a privileged instruction in normal cases, but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external interfaces.

			== Direction of transfer ==
			The actual transfer direction of the IOX and IOXT instructions is decoded from the device-register address, based on the following convention: the transfer direction is input (from device to CPU) if the device-register address is even.

			This means that all I/O device registers which need to be loaded from the CPU A register are assigned and odd device register address. Similarly I/O device input registers are assigned even addresses.

	== Device register address ==		== Device register address ==

2011-12-20T22:04:28Z

References: added another reference

← Older revision		Revision as of 22:04, 20 December 2011
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	== References ==		== References ==
	*{{ND-doc\|06.015.02\|(Programmed I/O, chapter 6.3, page 170-172)}}		*{{ND-doc\|06.015.02\|(Programmed I/O, chapter 6.3, page 170-172)}}
			*{{ND-doc\|06.026.1\| (The Input/Output Instructions IOX and IOXT, page 141)}}
	*{{ND-doc\|06.029.1\|(Input/Output Instructions, page 121-122)}}		*{{ND-doc\|06.029.1\|(Input/Output Instructions, page 121-122)}}


	[[Category:ND-100 instructions]]		[[Category:ND-100 instructions]]

2010-05-31T13:42:43Z

06.014.02 calls IOX "The Input/Output Instruction".

← Older revision		Revision as of 13:42, 31 May 2010
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	'''IOX''' is an assembly instruction used for [[programmed IO]] and it transfers data between a device I/O register and the CPU's [[A register]].		'''IOX''' is an assembly instruction used for [[programmed IO]], and it transfers data between a device I/O register and the CPU's [[A register]].

	IOX is a privileged instruction in normal cases but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external interfaces.		IOX (the Input/Output Instruction) is a privileged instruction in normal cases, but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external interfaces.

2010-05-31T13:40:12Z

Typo: external instruction -> external interfaces

← Older revision		Revision as of 13:40, 31 May 2010
Line 12:		Line 12:
	'''IOX''' is an assembly instruction used for [[programmed IO]] and it transfers data between a device I/O register and the CPU's [[A register]].		'''IOX''' is an assembly instruction used for [[programmed IO]] and it transfers data between a device I/O register and the CPU's [[A register]].

	IOX is a privileged instruction in normal cases but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external ~~instructions~~.		IOX is a privileged instruction in normal cases but if there is no OS running and the [[paging system]] is turned off then IOX is an unprivileged instruction. IOX and [[IOXT]] are the only instructions used to communicate with external interfaces.

2009-08-04T10:23:58Z

InstructionBox typo fix

2009-04-05T23:06:31Z

Rework on the page (+InstructionBox, +example, text from ND-06.029.1, etc)

@@ Line 1: / Line 1: @@
-'''IOX''' instruction is used for [[programmed IO]]. IOX is a privileged instruction in normal cases but if there is no OS running and the paging system is turned off then IOX is an unprivileged instruction.
+{{InstructionBox
-IOX and [[IOXT]] are the only instructions used to communicate with external instructions.
+|Mnemonic=IOX
-Bit 0-10 of the instruction code sets the direction and IO address. If bit 0 is zero then IOX reads the value from the IO register into register A. If bit 0 is one then IOX writes the contents of register A to the IO register.
+'''IOX''' is an assembly instruction used for [[programmed IO]] and it transfers data between a device I/O register and the CPU's [[A register]].
 == Se also ==
 * [[IOXT]] instruction
 == References ==
-*{{ND-doc|06.015|(Programmed I/O, chapter 6.3)}}
+*{{ND-doc|06.015.02|(Programmed I/O, chapter 6.3, page 170-172)}}
 [[Category:ND-100 instructions]]

2009-02-01T17:05:39Z

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