nuttx/arch/z80/include/z180/irq.h
2022-09-28 09:38:55 +08:00

236 lines
8.7 KiB
C

/****************************************************************************
* arch/z80/include/z180/irq.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* This file should never be included directly but, rather, only indirectly
* through nuttx/irq.h (via arch/irq.h)
*/
#ifndef __ARCH_Z80_INCLUDE_Z180_IRQ_H
#define __ARCH_Z80_INCLUDE_Z180_IRQ_H
/****************************************************************************
* Included Files
****************************************************************************/
#ifndef __ASSEMBLY__
# include <stdint.h>
#endif
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Z180 Interrupts */
/* Resets */
/* RST 0 is the power-up interrupt vector */
#define Z180_RST1 (0) /* RST 1 */
#define Z180_RST2 (1) /* RST 2 */
#define Z180_RST3 (2) /* RST 3 */
#define Z180_RST4 (3) /* RST 4 */
#define Z180_RST5 (4) /* RST 5 */
#define Z180_RST6 (5) /* RST 6 */
#define Z180_RST7 (6) /* RST 7 */
/* TRAP Interrupt
*
* The Z8X180 generates a non-maskable TRAP interrupt when an undefined Op
* Code fetch occurs. When a TRAP interrupt occurs the Z8X180 operates as
* follows:
*
* 1. The TRAP bit in the Interrupt TRAP/Control (ITC) register is set to 1.
* 2. The current PC (Program Counter) is saved on the stack.
* 3. The Z8X180 vectors to logical address 0 (which may or may not be the
* same as reset which vectors to physical address 0x00000).
*
* The state of the UFO (Undefined Fetch Object) bit in ITC allows TRAP
* manipulation software to correctly adjust the stacked PC, depending on
* whether the second or third byte of the Op Code generated the TRAP. If
* UFO is 0, the starting address of the invalid instruction is equal to
* the stacked PC-1. If UFO is 1, the starting address of the invalid
* instruction is equal to the stacked PC-2.
*/
#define Z180_TRAP (7)
/* INT0
*
* INT0 (only) has 3 different software programmable interrupt response
* modes: Mode 0, Mode 1 and Mode 2.
*
* - INT0 Mode 0. During the interrupt acknowledge cycle, an instruction
* is fetched from the data bus (DO-D7) at the rising edge of T3.
*
* - INT0 Mode 1. The PC is stacked and instruction execution restarts at
* logical address 0x0038.
*
* - INT0 Mode 2. The restart address is obtained by reading the contents
* of a table residing in memory. The vector table consists of up to
* 128 two-byte restart addresses stored in low byte, high byte order.
*
* This is similar to normal vector mode interrupts (like INT1 and 2):
* The 256-bit table address comes from I, however the lower-order 8
* bits of the vector is fetched from the data bus.
*/
#define Z180_INT0 (8)
/* Vector Interrupts
*
* Normal vector interrupts use a vector table with 16 entries (2 bytes
* per entry). Each entry holds the address of the interrupt handler.
* The vector table address is determined by 11-bits from the I and IL
* registers. The vector table must be aligned on 32-byte address
* boundaries.
*/
#define Z180_INT1 (9) /* Vector offset 0: External /INT1 */
#define Z180_INT2 (10) /* Vector offset 2: External /INT2 */
#define Z180_PRT0 (11) /* Vector offset 4: PRT channel 0 */
#define Z180_PRT1 (12) /* Vector offset 6: PRT channel 1 */
#define Z180_DMA0 (13) /* Vector offset 8: DMA channel 0 */
#define Z180_DMA1 (14) /* Vector offset 10: DMA Channel 1 */
#define Z180_CSIO (15) /* Vector offset 12: Clocked serial I/O */
#define Z180_ASCI0 (16) /* Vector offset 14: Async channel 0 */
#define Z180_ASCI1 (18) /* Vector offset 16: Async channel 1 */
#define Z180_UNUSED (19) /* Vector offset 18-20: unused */
#define Z180_IRQ_SYSTIMER Z180_RST7
#define NR_IRQS (20)
/* IRQ Stack Frame Format
*
* This stack frame is created on each interrupt. These registers are stored
* in the TCB to many context switches.
*/
#define XCPT_I (0) /* Offset 0: Saved I w/interrupt state in carry */
#define XCPT_BC (1) /* Offset 1: Saved BC register */
#define XCPT_DE (2) /* Offset 2: Saved DE register */
#define XCPT_IX (3) /* Offset 3: Saved IX register */
#define XCPT_IY (4) /* Offset 4: Saved IY register */
#define XCPT_SP (5) /* Offset 5: Offset to SP at time of interrupt */
#define XCPT_HL (6) /* Offset 6: Saved HL register */
#define XCPT_AF (7) /* Offset 7: Saved AF register */
#define XCPT_PC (8) /* Offset 8: Offset to PC at time of interrupt */
#define XCPTCONTEXT_REGS (9)
#define XCPTCONTEXT_SIZE (2 * XCPTCONTEXT_REGS)
/****************************************************************************
* Public Types
****************************************************************************/
#ifndef __ASSEMBLY__
/* This is the type of the register save array */
typedef uint16_t chipreg_t;
/* Common Area 1 holds the code and data that is unique to a particular task
* and shared by all pthreads created from that task. Each task will then
* have its own copy of struct z180_cbr_s. This structure is created with
* a reference count of one when the task is created.
*
* When the task creates additional threads, the reference count is
* incremented and the CBR value is shared. When each thread exits, the
* reference count id decremented. When the reference count is decremented,
* the physical memory underlying the CBR is finally released.
*/
struct z180_cbr_s
{
uint8_t cbr; /* The CBR value used by the thread */
uint8_t crefs; /* The number of task groups using this CBR value (0 or 1) */
uint8_t pages; /* The number of 4KB pages of physical memory in the allocation */
};
/* This struct defines the way the registers and z180-state information are
* stored.
*/
struct xcptcontext
{
/* Register save area */
chipreg_t regs[XCPTCONTEXT_REGS];
/* The following function pointer is non-zero if there
* are pending signals to be processed.
*/
CODE void *sigdeliver; /* Actual type is sig_deliver_t */
/* The following retains that state during signal execution
*
* REVISIT: Because there is only one copy of these save areas,
* only a single signal handler can be active. This precludes
* queuing of signal actions. As a result, signals received while
* another signal handler is executing will be ignored!
*/
uint16_t saved_pc; /* Saved return address */
uint16_t saved_i; /* Saved interrupt state */
};
#endif
/****************************************************************************
* Inline functions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifndef __ASSEMBLY__
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/* Name: up_irq_save, up_irq_restore, and friends.
*
* NOTE: This function should never be called from application code and,
* as a general rule unless you really know what you are doing, this
* function should not be called directly from operation system code either:
* Typically, the wrapper functions, enter_critical_section() and
* leave_critical section(), are probably what you really want.
*/
irqstate_t up_irq_save(void) __naked;
void up_irq_restore(irqstate_t flags) __naked;
irqstate_t up_irq_enable(void);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif
#endif /* __ARCH_Z80_INCLUDE_Z180_IRQ_H */