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author Miodrag Milanovic <mmicko@gmail.com>2015-09-30 17:21:14 +0200
committer Miodrag Milanovic <mmicko@gmail.com>2015-09-30 17:21:14 +0200
commit1fc48ce120a376c288daeeed98daccecf1b60d7b (patch)
tree72cefcede17f3a27fa8256b43bfac9756db82312 /src/mame/machine/6883sam.h
parent87a576c55501bd7125b51ca786a010229669df0e (diff)
move mess into mame (nw)
Diffstat (limited to 'src/mame/machine/6883sam.h')
-rw-r--r--src/mame/machine/6883sam.h266
1 files changed, 266 insertions, 0 deletions
diff --git a/src/mame/machine/6883sam.h b/src/mame/machine/6883sam.h
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+++ b/src/mame/machine/6883sam.h
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+// license:BSD-3-Clause
+// copyright-holders:Nathan Woods
+/***************************************************************************
+
+ 6883sam.h
+
+ Motorola 6883 Synchronous Address Multiplexer
+
+***************************************************************************/
+
+#pragma once
+
+#ifndef __6883SAM__
+#define __6883SAM__
+
+#include "emu.h"
+
+#define MCFG_SAM6883_ADD(_tag, _clock, _cputag, _cpuspace) \
+ MCFG_DEVICE_ADD(_tag, SAM6883, _clock) \
+ sam6883_device::configure_cpu(*device, _cputag, _cpuspace);
+
+#define MCFG_SAM6883_RES_CALLBACK(_read) \
+ devcb = &sam6883_device::set_res_rd_callback(*device, DEVCB_##_read);
+
+
+//**************************************************************************
+// SAM6883 CORE
+//**************************************************************************
+
+// base class so that GIME emulation can use some functionality
+class sam6883_friend_device
+{
+public:
+ sam6883_friend_device() { m_cpu = NULL; m_sam_state = 0x0000; }
+
+protected:
+ // SAM state constants
+ static const UINT16 SAM_STATE_TY = 0x8000;
+ static const UINT16 SAM_STATE_M1 = 0x4000;
+ static const UINT16 SAM_STATE_M0 = 0x2000;
+ static const UINT16 SAM_STATE_R1 = 0x1000;
+ static const UINT16 SAM_STATE_R0 = 0x0800;
+ static const UINT16 SAM_STATE_P1 = 0x0400;
+ static const UINT16 SAM_STATE_F6 = 0x0200;
+ static const UINT16 SAM_STATE_F5 = 0x0100;
+ static const UINT16 SAM_STATE_F4 = 0x0080;
+ static const UINT16 SAM_STATE_F3 = 0x0040;
+ static const UINT16 SAM_STATE_F2 = 0x0020;
+ static const UINT16 SAM_STATE_F1 = 0x0010;
+ static const UINT16 SAM_STATE_F0 = 0x0008;
+ static const UINT16 SAM_STATE_V2 = 0x0004;
+ static const UINT16 SAM_STATE_V1 = 0x0002;
+ static const UINT16 SAM_STATE_V0 = 0x0001;
+
+ // incidentals
+ cpu_device * m_cpu;
+
+ // device state
+ UINT16 m_sam_state;
+
+ ATTR_FORCE_INLINE UINT16 display_offset(void)
+ {
+ return ((m_sam_state & (SAM_STATE_F0|SAM_STATE_F1|SAM_STATE_F2|SAM_STATE_F3|SAM_STATE_F4|SAM_STATE_F5|SAM_STATE_F6)) / SAM_STATE_F0) << 9;
+ }
+
+ ATTR_FORCE_INLINE UINT16 alter_sam_state(offs_t offset)
+ {
+ /* determine the mask */
+ UINT16 mask = 1 << (offset >> 1);
+
+ /* determine the new state */
+ UINT16 new_state;
+ if (offset & 0x0001)
+ new_state = m_sam_state | mask;
+ else
+ new_state = m_sam_state & ~mask;
+
+ /* specify the new state */
+ UINT16 xorval = m_sam_state ^ new_state;
+ m_sam_state = new_state;
+ return xorval;
+ }
+
+ void update_cpu_clock(void);
+};
+
+class sam6883_device : public device_t, public sam6883_friend_device
+{
+public:
+ sam6883_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+ template<class _Object> static devcb_base &set_res_rd_callback(device_t &device, _Object object) { return downcast<sam6883_device &>(device).m_read_res.set_callback(object); }
+
+ static void configure_cpu(device_t &device, const char *tag, address_spacenum space)
+ {
+ sam6883_device &dev = downcast<sam6883_device &>(device);
+ dev.m_cpu_tag = tag;
+ dev.m_cpu_space_ref = space;
+ }
+
+ // called to configure banks
+ void configure_bank(int bank, UINT8 *memory, UINT32 memory_size, bool is_read_only);
+ void configure_bank(int bank, read8_delegate rhandler, write8_delegate whandler);
+
+ // typically called by VDG
+ ATTR_FORCE_INLINE DECLARE_READ8_MEMBER( display_read )
+ {
+ if (offset == (offs_t) ~0)
+ {
+ /* the VDG is telling the counter to reset */
+ m_counter = display_offset();
+ m_counter_xdiv = 0;
+ m_counter_ydiv = 0;
+ }
+ else if ((offset & 1) != (m_counter & 0x0001))
+ {
+ /* DA0 has been toggled - first bump B0-B3 of the counter */
+ bool bit3_carry = (m_counter & 0x000F) == 0x000F;
+ m_counter = (m_counter & ~0x000F) | ((m_counter + 1) & 0x000F);
+
+ /* and apply the carry (if applicable */
+ if (bit3_carry)
+ counter_carry_bit3();
+ }
+ return m_read_res((m_counter & m_counter_mask) | m_counter_or);
+ }
+
+ DECLARE_WRITE_LINE_MEMBER( hs_w );
+
+ // typically called by machine
+ address_space *mpu_address_space(void) const { return m_cpu_space; }
+ void set_bank_offset(int bank, offs_t offset);
+
+protected:
+ // device-level overrides
+ virtual void device_start();
+ virtual void device_reset();
+ virtual void device_post_load();
+
+private:
+ // represents an external memory bank - memory or IO that the SAM
+ // points to with the S2/S1/S0 output
+ struct sam_bank
+ {
+ UINT8 * m_memory;
+ UINT32 m_memory_size;
+ offs_t m_memory_offset;
+ bool m_memory_read_only;
+ read8_delegate m_rhandler;
+ write8_delegate m_whandler;
+ };
+
+ // represents one of the memory "spaces" (e.g. - $8000-$9FFF) that
+ // can ultimately point to a bank
+ template<UINT16 _addrstart, UINT16 _addrend>
+ class sam_space
+ {
+ public:
+ sam_space(sam6883_device &owner);
+ void point(const sam_bank *bank, UINT16 offset, UINT16 mask);
+
+ private:
+ sam6883_device & m_owner;
+ memory_bank * m_read_bank;
+ memory_bank * m_write_bank;
+ UINT16 m_mask;
+
+ address_space &cpu_space() const;
+ void point_specific_bank(const sam_bank *bank, UINT16 offset, UINT16 mask, memory_bank *&memory_bank, INT32 addrstart, INT32 addrend, bool is_write);
+ };
+
+ const char * m_cpu_tag;
+ address_spacenum m_cpu_space_ref;
+
+ // incidentals
+ address_space * m_cpu_space;
+ devcb_read8 m_read_res;
+ sam_bank m_banks[8];
+ sam_space<0x0000, 0x7FFF> m_space_0000;
+ sam_space<0x8000, 0x9FFF> m_space_8000;
+ sam_space<0xA000, 0xBFFF> m_space_A000;
+ sam_space<0xC000, 0xFEFF> m_space_C000;
+ sam_space<0xFF00, 0xFF1F> m_space_FF00;
+ sam_space<0xFF20, 0xFF3F> m_space_FF20;
+ sam_space<0xFF40, 0xFF5F> m_space_FF40;
+ sam_space<0xFF60, 0xFFBF> m_space_FF60;
+ sam_space<0xFFE0, 0xFFFF> m_space_FFE0;
+ UINT16 m_counter_mask;
+ UINT16 m_counter_or;
+
+ // SAM state
+ UINT16 m_counter;
+ UINT8 m_counter_xdiv;
+ UINT8 m_counter_ydiv;
+
+ // dummy scratch memory
+ UINT8 m_dummy[0x8000];
+
+ // typically called by CPU
+ DECLARE_READ8_MEMBER( read );
+ DECLARE_WRITE8_MEMBER( write );
+
+ // called when there is a carry out of bit 3 on the counter
+ ATTR_FORCE_INLINE void counter_carry_bit3(void)
+ {
+ UINT8 x_division;
+ switch((m_sam_state & (SAM_STATE_V2|SAM_STATE_V1|SAM_STATE_V0)) / SAM_STATE_V0)
+ {
+ case 0x00: x_division = 1; break;
+ case 0x01: x_division = 3; break;
+ case 0x02: x_division = 1; break;
+ case 0x03: x_division = 2; break;
+ case 0x04: x_division = 1; break;
+ case 0x05: x_division = 1; break;
+ case 0x06: x_division = 1; break;
+ case 0x07: x_division = 1; break;
+ default:
+ fatalerror("Should not get here\n");
+ return;
+ }
+
+ if (++m_counter_xdiv >= x_division)
+ {
+ m_counter_xdiv = 0;
+ m_counter ^= 0x0010;
+ if ((m_counter & 0x0010) == 0x0000)
+ counter_carry_bit4();
+ }
+ }
+
+ // called when there is a carry out of bit 4 on the counter
+ ATTR_FORCE_INLINE void counter_carry_bit4(void)
+ {
+ UINT8 y_division;
+ switch((m_sam_state & (SAM_STATE_V2|SAM_STATE_V1|SAM_STATE_V0)) / SAM_STATE_V0)
+ {
+ case 0x00: y_division = 12; break;
+ case 0x01: y_division = 1; break;
+ case 0x02: y_division = 3; break;
+ case 0x03: y_division = 1; break;
+ case 0x04: y_division = 2; break;
+ case 0x05: y_division = 1; break;
+ case 0x06: y_division = 1; break;
+ case 0x07: y_division = 1; break;
+ default:
+ fatalerror("Should not get here\n");
+ return;
+ }
+
+ if (++m_counter_ydiv >= y_division)
+ {
+ m_counter_ydiv = 0;
+ m_counter += 0x0020;
+ }
+ }
+
+ // other members
+ void configure_bank(int bank, UINT8 *memory, UINT32 memory_size, bool is_read_only, read8_delegate rhandler, write8_delegate whandler);
+ void horizontal_sync(void);
+ void update_state(void);
+ void update_memory(void);
+};
+
+extern const device_type SAM6883;
+
+#endif /* __6883SAM__ */