IRQs and ISRs for the SH4's CPU More...

Topics
	Context
	Thread execution state and accessors

	Control Flow
	Methods for managing control flow within an irq_handler.

	Exception type offsets
	Offsets within exception types

	Handlers
	API for managing IRQ handlers

	Mask
	Accessors and modifiers of the IMASK state.

	State
	Methods for querying active IRQ information.

Files
file	irq.h
	Interrupt and exception handling.

Macros
#define	TIMER_IRQ EXC_TMU0_TUNI0
	The value of the timer IRQ.

#define	irq_disable_scoped()
	Disable interrupts with scope management.

Enumerations
enum	irq_t { EXC_RESET_POWERON = 0x0000 , EXC_RESET_MANUAL = 0x0020 , EXC_RESET_UDI = 0x0000 , EXC_ITLB_MULTIPLE = 0x0140 , EXC_DTLB_MULTIPLE = 0x0140 , EXC_USER_BREAK_PRE = 0x01e0 , EXC_INSTR_ADDRESS = 0x00e0 , EXC_ITLB_MISS = 0x0040 , EXC_ITLB_PV = 0x00a0 , EXC_ILLEGAL_INSTR = 0x0180 , EXC_SLOT_ILLEGAL_INSTR = 0x01a0 , EXC_GENERAL_FPU = 0x0800 , EXC_SLOT_FPU = 0x0820 , EXC_DATA_ADDRESS_READ = 0x00e0 , EXC_DATA_ADDRESS_WRITE = 0x0100 , EXC_DTLB_MISS_READ = 0x0040 , EXC_DTLB_MISS_WRITE = 0x0060 , EXC_DTLB_PV_READ = 0x00a0 , EXC_DTLB_PV_WRITE = 0x00c0 , EXC_FPU = 0x0120 , EXC_INITIAL_PAGE_WRITE = 0x0080 , EXC_TRAPA = 0x0160 , EXC_USER_BREAK_POST = 0x01e0 , EXC_NMI = 0x01c0 , EXC_IRQ0 = 0x0200 , EXC_IRQ1 = 0x0220 , EXC_IRQ2 = 0x0240 , EXC_IRQ3 = 0x0260 , EXC_IRQ4 = 0x0280 , EXC_IRQ5 = 0x02a0 , EXC_IRQ6 = 0x02c0 , EXC_IRQ7 = 0x02e0 , EXC_IRQ8 = 0x0300 , EXC_IRQ9 = 0x0320 , EXC_IRQA = 0x0340 , EXC_IRQB = 0x0360 , EXC_IRQC = 0x0380 , EXC_IRQD = 0x03a0 , EXC_IRQE = 0x03c0 , EXC_TMU0_TUNI0 = 0x0400 , EXC_TMU1_TUNI1 = 0x0420 , EXC_TMU2_TUNI2 = 0x0440 , EXC_TMU2_TICPI2 = 0x0460 , EXC_RTC_ATI = 0x0480 , EXC_RTC_PRI = 0x04a0 , EXC_RTC_CUI = 0x04c0 , EXC_SCI_ERI = 0x04e0 , EXC_SCI_RXI = 0x0500 , EXC_SCI_TXI = 0x0520 , EXC_SCI_TEI = 0x0540 , EXC_WDT_ITI = 0x0560 , EXC_REF_RCMI = 0x0580 , EXC_REF_ROVI = 0x05a0 , EXC_UDI = 0x0600 , EXC_GPIO_GPIOI = 0x0620 , EXC_DMAC_DMTE0 = 0x0640 , EXC_DMAC_DMTE1 = 0x0660 , EXC_DMAC_DMTE2 = 0x0680 , EXC_DMAC_DMTE3 = 0x06a0 , EXC_DMA_DMAE = 0x06c0 , EXC_SCIF_ERI = 0x0700 , EXC_SCIF_RXI = 0x0720 , EXC_SCIF_BRI = 0x0740 , EXC_SCIF_TXI = 0x0760 , EXC_DOUBLE_FAULT = 0x0ff0 , EXC_UNHANDLED_EXC = 0x0fe0 }
	Interrupt exception codes. More...

Detailed Description

IRQs and ISRs for the SH4's CPU

This is an API for managing interrupts, their masks, and their handler routines along with thread context information.

Warning: This is a low-level, internal kernel API. Many of these interrupts are utilized by various KOS drivers and have higher-level APIs for hooking into them. Care must be taken to not interfere with the IRQ handling which is being done by in-use KOS drivers.

Macro Definition Documentation

◆ irq_disable_scoped

#define irq_disable_scoped ( )

Value:

__irq_disable_scoped(__LINE__)

Disable interrupts with scope management.

This macro will disable interrupts, similarly to irq_disable(), with the difference that the interrupt state will automatically be restored once the execution exits the functional block in which the macro was called.

◆ TIMER_IRQ

#define TIMER_IRQ EXC_TMU0_TUNI0

The value of the timer IRQ.

Enumeration Type Documentation

◆ irq_t

enum irq_t

Interrupt exception codes.

Dreamcast-specific exception codes. Used to identify the source or type of an interrupt. Each exception code is of a certain "type" which dictates how the interrupt is generated and handled.

List of exception types:

Type	Description
`RESET`	Caused by system reset. Uncatchable and fatal. Automatically branch to address `0xA0000000`.
`REEXEC`	Restarts current instruction after interrupt processing. Context PC is the triggering instruction.
`POST`	Continues with next instruciton after interrupt processing. Context PC is the next instruction.
`SOFT`	Software-driven exceptions for triggering interrupts upon special events.
`UNUSED`	Known to not be present and usable with the DC's SH4 configuration.

List of exception codes:

Enumerator
EXC_RESET_POWERON	`[RESET ]` Power-on reset
EXC_RESET_MANUAL	`[RESET ]` Manual reset
EXC_RESET_UDI	`[RESET ]` Hitachi UDI reset
EXC_ITLB_MULTIPLE	`[RESET ]` Instruction TLB multiple hit
EXC_DTLB_MULTIPLE	`[RESET ]` Data TLB multiple hit
EXC_USER_BREAK_PRE	`[REEXEC]` User break before instruction
EXC_INSTR_ADDRESS	`[REEXEC]` Instruction address
EXC_ITLB_MISS	`[REEXEC]` Instruction TLB miss
EXC_ITLB_PV	`[REEXEC]` Instruction TLB protection violation
EXC_ILLEGAL_INSTR	`[REEXEC]` Illegal instruction
EXC_SLOT_ILLEGAL_INSTR	`[REEXEC]` Slot illegal instruction
EXC_GENERAL_FPU	`[REEXEC]` General FPU exception
EXC_SLOT_FPU	`[REEXEC]` Slot FPU exception
EXC_DATA_ADDRESS_READ	`[REEXEC]` Data address (read)
EXC_DATA_ADDRESS_WRITE	`[REEXEC]` Data address (write)
EXC_DTLB_MISS_READ	`[REEXEC]` Data TLB miss (read)
EXC_DTLB_MISS_WRITE	`[REEXEC]` Data TLB miss (write)
EXC_DTLB_PV_READ	`[REEXEC]` Data TLB protection violation (read)
EXC_DTLB_PV_WRITE	`[REEXEC]` Data TLB protection violation (write)
EXC_FPU	`[REEXEC]` FPU exception
EXC_INITIAL_PAGE_WRITE	`[REEXEC]` Initial page write exception
EXC_TRAPA	`[POST ]` Unconditional trap (`TRAPA`)
EXC_USER_BREAK_POST	`[POST ]` User break after instruction
EXC_NMI	`[POST ]` Nonmaskable interrupt
EXC_IRQ0	`[POST ]` External IRQ request (level 0)
EXC_IRQ1	`[POST ]` External IRQ request (level 1)
EXC_IRQ2	`[POST ]` External IRQ request (level 2)
EXC_IRQ3	`[POST ]` External IRQ request (level 3)
EXC_IRQ4	`[POST ]` External IRQ request (level 4)
EXC_IRQ5	`[POST ]` External IRQ request (level 5)
EXC_IRQ6	`[POST ]` External IRQ request (level 6)
EXC_IRQ7	`[POST ]` External IRQ request (level 7)
EXC_IRQ8	`[POST ]` External IRQ request (level 8)
EXC_IRQ9	`[POST ]` External IRQ request (level 9)
EXC_IRQA	`[POST ]` External IRQ request (level 10)
EXC_IRQB	`[POST ]` External IRQ request (level 11)
EXC_IRQC	`[POST ]` External IRQ request (level 12)
EXC_IRQD	`[POST ]` External IRQ request (level 13)
EXC_IRQE	`[POST ]` External IRQ request (level 14)
EXC_TMU0_TUNI0	`[POST ]` TMU0 underflow
EXC_TMU1_TUNI1	`[POST ]` TMU1 underflow
EXC_TMU2_TUNI2	`[POST ]` TMU2 underflow
EXC_TMU2_TICPI2	`[UNUSED]` TMU2 input capture
EXC_RTC_ATI	`[UNUSED]` RTC alarm interrupt
EXC_RTC_PRI	`[UNUSED]` RTC periodic interrupt
EXC_RTC_CUI	`[UNUSED]` RTC carry interrupt
EXC_SCI_ERI	`[UNUSED]` SCI Error receive
EXC_SCI_RXI	`[UNUSED]` SCI Receive ready
EXC_SCI_TXI	`[UNUSED]` SCI Transmit ready
EXC_SCI_TEI	`[UNUSED]` SCI Transmit error
EXC_WDT_ITI	`[POST ]` Watchdog timer
EXC_REF_RCMI	`[POST ]` Memory refresh compare-match interrupt
EXC_REF_ROVI	`[POST ]` Memory refresh counter overflow interrupt
EXC_UDI	`[POST ]` Hitachi UDI
EXC_GPIO_GPIOI	`[POST ]` I/O port interrupt
EXC_DMAC_DMTE0	`[POST ]` DMAC transfer end (channel 0)
EXC_DMAC_DMTE1	`[POST ]` DMAC transfer end (channel 1)
EXC_DMAC_DMTE2	`[POST ]` DMAC transfer end (channel 2)
EXC_DMAC_DMTE3	`[POST ]` DMAC transfer end (channel 3)
EXC_DMA_DMAE	`[POST ]` DMAC address error
EXC_SCIF_ERI	`[POST ]` SCIF Error receive
EXC_SCIF_RXI	`[POST ]` SCIF Receive ready
EXC_SCIF_BRI	`[POST ]` SCIF break
EXC_SCIF_TXI	`[POST ]` SCIF Transmit ready
EXC_DOUBLE_FAULT	`[SOFT ]` Exception happened in an ISR
EXC_UNHANDLED_EXC	`[SOFT ]` Exception went unhandled

Topics

Files