MAME Interrupt Function Review - Revision history

Aaron at 04:59, 21 February 2007

2007-02-21T04:59:03Z

← Older revision		Revision as of 06:59, 21 February 2007
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	The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line).		The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line).


	* '''ASSERT_LINE''' - raise the interrupt line and hold it there indefinitely		* '''ASSERT_LINE''' - raise the interrupt line and hold it there indefinitely

	* '''CLEAR_LINE''' - lower the interrupt line and hold it there indefinitely		* '''CLEAR_LINE''' - lower the interrupt line and hold it there indefinitely

	* '''PULSE_LINE''' - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE		* '''PULSE_LINE''' - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE

	* '''HOLD_LINE''' - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)		* '''HOLD_LINE''' - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)


	On most CPUs, most interrupt lines are level-sensitive, which means that they will continue to generate interrupts as long as they are asserted. This generally means that you can't use PULSE_LINE because pulsing an interrupt line is instantaneous. In real life, the CPU would never respond to such a pulse because it is too short.		On most CPUs, most interrupt lines are level-sensitive, which means that they will continue to generate interrupts as long as they are asserted. This generally means that you can't use PULSE_LINE because pulsing an interrupt line is instantaneous. In real life, the CPU would never respond to such a pulse because it is too short.

Aaron at 08:58, 5 February 2007

2007-02-05T08:58:23Z

← Older revision		Revision as of 10:58, 5 February 2007
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	'''ASSERT_LINE''' - raise the interrupt line and hold it there indefinitely		* '''ASSERT_LINE''' - raise the interrupt line and hold it there indefinitely

	'''CLEAR_LINE''' - lower the interrupt line and hold it there indefinitely		* '''CLEAR_LINE''' - lower the interrupt line and hold it there indefinitely

	'''PULSE_LINE''' - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE		* '''PULSE_LINE''' - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE

	'''HOLD_LINE''' - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)		* '''HOLD_LINE''' - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)

AndrewGardner at 05:49, 4 February 2007

2007-02-04T05:49:43Z

← Older revision		Revision as of 07:49, 4 February 2007
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	ASSERT_LINE - raise the interrupt line and hold it there indefinitely		'''ASSERT_LINE''' - raise the interrupt line and hold it there indefinitely

	CLEAR_LINE - lower the interrupt line and hold it there indefinitely		'''CLEAR_LINE''' - lower the interrupt line and hold it there indefinitely

	PULSE_LINE - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE		'''PULSE_LINE''' - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE

	HOLD_LINE - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)		'''HOLD_LINE''' - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)

AndrewGardner at 05:40, 4 February 2007

2007-02-04T05:40:23Z

← Older revision		Revision as of 07:40, 4 February 2007
Line 1:		Line 1:
	The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line).		The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line).


	ASSERT_LINE - raise the interrupt line and hold it there indefinitely		ASSERT_LINE - raise the interrupt line and hold it there indefinitely
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	HOLD_LINE - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)		HOLD_LINE - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)


	On most CPUs, most interrupt lines are level-sensitive, which means that they will continue to generate interrupts as long as they are asserted. This generally means that you can't use PULSE_LINE because pulsing an interrupt line is instantaneous. In real life, the CPU would never respond to such a pulse because it is too short.		On most CPUs, most interrupt lines are level-sensitive, which means that they will continue to generate interrupts as long as they are asserted. This generally means that you can't use PULSE_LINE because pulsing an interrupt line is instantaneous. In real life, the CPU would never respond to such a pulse because it is too short.

AndrewGardner: New page: The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line). ASSERT_LINE - raise the interrupt line and hold it there indefinitely CLEAR_LINE - lower the int...

2007-02-04T05:39:36Z

New page: The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line). ASSERT_LINE - raise the interrupt line and hold it there indefinitely CLEAR_LINE - lower the int...

New page

The following refers to the MAME core IRQ handling functions (eg. cpunum_set_input_line).

ASSERT_LINE - raise the interrupt line and hold it there indefinitely

CLEAR_LINE - lower the interrupt line and hold it there indefinitely

PULSE_LINE - instantaneously do an ASSERT_LINE followed by a CLEAR_LINE

HOLD_LINE - raise the interrupt line and hold it there until the interrupt is acknowledged by the CPU (note that this really only applies to those few CPUs with a full acknowledge cycles; the Z80 is the primary one -- all other uses are cheating)

On most CPUs, most interrupt lines are level-sensitive, which means that they will continue to generate interrupts as long as they are asserted. This generally means that you can't use PULSE_LINE because pulsing an interrupt line is instantaneous. In real life, the CPU would never respond to such a pulse because it is too short.

Some CPUs have interrupt lines that are edge-sensitive, which means they will detect a state change from CLEAR_LINE to ASSERT_LINE and latch that information internally. Then they will take the interrupt and clear the latch. These are the only types of interrupts that can be used with PULSE_LINE.

Some CPUs let you program the interrupt lines to be either edge or level sensitive.

There may be helper functions in the future that allow the driver author to assert a line for a set period of time.