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-rw-r--r--src/devices/bus/saturn/dram.cpp96
1 files changed, 96 insertions, 0 deletions
diff --git a/src/devices/bus/saturn/dram.cpp b/src/devices/bus/saturn/dram.cpp
new file mode 100644
index 00000000000..d1078fcc722
--- /dev/null
+++ b/src/devices/bus/saturn/dram.cpp
@@ -0,0 +1,96 @@
+// license:BSD-3-Clause
+// copyright-holders:Fabio Priuli
+/***********************************************************************************************************
+
+ Saturn cart emulation
+
+ ***********************************************************************************************************/
+
+
+#include "emu.h"
+#include "dram.h"
+
+
+//-------------------------------------------------
+// constructor
+//-------------------------------------------------
+
+const device_type SATURN_DRAM_8MB = &device_creator<saturn_dram8mb_device>;
+const device_type SATURN_DRAM_32MB = &device_creator<saturn_dram32mb_device>;
+
+
+saturn_dram_device::saturn_dram_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
+ : device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+ device_sat_cart_interface( mconfig, *this )
+{
+}
+
+saturn_dram8mb_device::saturn_dram8mb_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : saturn_dram_device(mconfig, SATURN_DRAM_8MB, "Saturn Data RAM 8Mbit Cart", tag, owner, clock, "sat_dram_8mb", __FILE__)
+{
+ m_cart_type = 0x5a;
+}
+
+saturn_dram32mb_device::saturn_dram32mb_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : saturn_dram_device(mconfig, SATURN_DRAM_32MB, "Saturn Data RAM 32Mbit Cart", tag, owner, clock, "sat_dram_32mb", __FILE__)
+{
+ m_cart_type = 0x5c;
+}
+
+
+//-------------------------------------------------
+// mapper specific start/reset
+//-------------------------------------------------
+
+void saturn_dram_device::device_start()
+{
+}
+
+void saturn_dram_device::device_reset()
+{
+}
+
+
+/*-------------------------------------------------
+ mapper specific handlers
+ -------------------------------------------------*/
+
+// RAM: two DRAM chips are present in the cart, thus accesses only go up to m_size/2!
+
+READ32_MEMBER(saturn_dram_device::read_ext_dram0)
+{
+ if (offset < (0x400000/2)/4)
+ return m_ext_dram0[offset % m_ext_dram0.size()];
+ else
+ {
+ popmessage("DRAM0 read beyond its boundary! offs: %X\n", offset);
+ return 0xffffffff;
+ }
+}
+
+READ32_MEMBER(saturn_dram_device::read_ext_dram1)
+{
+ if (offset < (0x400000/2)/4)
+ return m_ext_dram1[offset % m_ext_dram1.size()];
+ else
+ {
+ popmessage("DRAM1 read beyond its boundary! offs: %X\n", offset);
+ return 0xffffffff;
+ }
+}
+
+WRITE32_MEMBER(saturn_dram_device::write_ext_dram0)
+{
+ if (offset < (0x400000/2)/4)
+ COMBINE_DATA(&m_ext_dram0[offset % m_ext_dram0.size()]);
+ else
+ popmessage("DRAM0 write beyond its boundary! offs: %X data: %X\n", offset, data);
+}
+
+WRITE32_MEMBER(saturn_dram_device::write_ext_dram1)
+{
+ if (offset < (0x400000/2)/4)
+ COMBINE_DATA(&m_ext_dram1[offset % m_ext_dram1.size()]);
+ else
+ popmessage("DRAM1 write beyond its boundary! offs: %X data: %X\n", offset, data);
+}