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-rw-r--r--src/devices/cpu/m68000/m68kcommon.h75
1 files changed, 75 insertions, 0 deletions
diff --git a/src/devices/cpu/m68000/m68kcommon.h b/src/devices/cpu/m68000/m68kcommon.h
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+++ b/src/devices/cpu/m68000/m68kcommon.h
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+// license:BSD-3-Clause
+// copyright-holders:Olivier Galibert
+
+#ifndef MAME_CPU_M68000_M68KCOMMON_H
+#define MAME_CPU_M68000_M68KCOMMON_H
+
+#pragma once
+
+/* There are 7 levels of interrupt to the 68K.
+ * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI).
+ *
+ * If set_interrupt_mixer(false) has been called, the 3 interrupt lines
+ * are modeled instead, as numbers 0-2.
+ */
+constexpr int M68K_IRQ_NONE = 0;
+constexpr int M68K_IRQ_1 = 1;
+constexpr int M68K_IRQ_2 = 2;
+constexpr int M68K_IRQ_3 = 3;
+constexpr int M68K_IRQ_4 = 4;
+constexpr int M68K_IRQ_5 = 5;
+constexpr int M68K_IRQ_6 = 6;
+constexpr int M68K_IRQ_7 = 7;
+
+constexpr int M68K_IRQ_IPL0 = 0;
+constexpr int M68K_IRQ_IPL1 = 1;
+constexpr int M68K_IRQ_IPL2 = 2;
+
+enum
+{
+ // NOTE: M68K_SP fetches the current SP, be it USP, ISP, or MSP
+ M68K_PC = STATE_GENPC, M68K_SP = 1, M68K_ISP, M68K_USP, M68K_MSP, M68K_SR, M68K_VBR,
+ M68K_SFC, M68K_DFC, M68K_CACR, M68K_CAAR, M68K_IR, M68K_PREF_ADDR, M68K_PREF_DATA,
+ M68K_D0, M68K_D1, M68K_D2, M68K_D3, M68K_D4, M68K_D5, M68K_D6, M68K_D7,
+ M68K_A0, M68K_A1, M68K_A2, M68K_A3, M68K_A4, M68K_A5, M68K_A6, M68K_A7,
+ M68K_FP0, M68K_FP1, M68K_FP2, M68K_FP3, M68K_FP4, M68K_FP5, M68K_FP6, M68K_FP7,
+ M68K_FPSR, M68K_FPCR, M68K_CRP_LIMIT, M68K_CRP_APTR, M68K_SRP_LIMIT, M68K_SRP_APTR,
+ M68K_MMU_TC, M68K_TT0, M68K_TT1, M68K_MMU_SR, M68K_ITT0, M68K_ITT1,
+ M68K_DTT0, M68K_DTT1, M68K_URP_APTR
+};
+
+class m68000_base_device : public cpu_device
+{
+public:
+ enum {
+ AS_CPU_SPACE = 4,
+ AS_USER_PROGRAM = 5,
+ AS_USER_OPCODES = 6,
+ };
+
+ static constexpr u8 autovector(int level) { return 0x18 + level; }
+ void autovectors_map(address_map &map) ATTR_COLD;
+
+ void set_cpu_space(int space_id) { m_cpu_space_id = space_id; }
+ void set_interrupt_mixer(bool enable) { m_interrupt_mixer = enable; }
+ auto reset_cb() { return m_reset_cb.bind(); }
+
+ virtual bool execute_input_edge_triggered(int inputnum) const noexcept override { return m_interrupt_mixer ? inputnum == M68K_IRQ_7 : false; }
+
+ virtual bool supervisor_mode() const noexcept = 0;
+ virtual u16 get_fc() const noexcept = 0;
+
+protected:
+ bool m_interrupt_mixer; // Indicates whether to put a virtual 8->3 priority mixer on the input lines
+ int m_cpu_space_id; // CPU space address space id
+ devcb_write_line m_reset_cb;
+
+ m68000_base_device(const machine_config &mconfig, const device_type type, const char *tag, device_t *owner, u32 clock) :
+ cpu_device(mconfig, type, tag, owner, clock),
+ m_interrupt_mixer(true),
+ m_cpu_space_id(AS_CPU_SPACE),
+ m_reset_cb(*this)
+ { }
+};
+
+#endif