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-rw-r--r--src/devices/bus/dmv/k233.cpp89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/devices/bus/dmv/k233.cpp b/src/devices/bus/dmv/k233.cpp
new file mode 100644
index 00000000000..859b8b7f8f8
--- /dev/null
+++ b/src/devices/bus/dmv/k233.cpp
@@ -0,0 +1,89 @@
+// license:BSD-3-Clause
+// copyright-holders:Sandro Ronco
+/***************************************************************************
+
+ K233 16K Shared RAM
+
+***************************************************************************/
+
+#include "emu.h"
+#include "k233.h"
+
+
+/***************************************************************************
+ IMPLEMENTATION
+***************************************************************************/
+
+//**************************************************************************
+// GLOBAL VARIABLES
+//**************************************************************************
+
+const device_type DMV_K233 = &device_creator<dmv_k233_device>;
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// dmv_k233_device - constructor
+//-------------------------------------------------
+
+dmv_k233_device::dmv_k233_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : device_t(mconfig, DMV_K233, "K233 16K Shared RAM", tag, owner, clock, "dmv_k233", __FILE__),
+ device_dmvslot_interface( mconfig, *this )
+{
+}
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void dmv_k233_device::device_start()
+{
+ m_ram = machine().memory().region_alloc( "sharedram", 0x4000, 1, ENDIANNESS_LITTLE )->base();
+}
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void dmv_k233_device::device_reset()
+{
+ m_enabled = false;
+}
+
+void dmv_k233_device::io_write(address_space &space, int ifsel, offs_t offset, UINT8 data)
+{
+ if (ifsel == 1)
+ m_enabled = !m_enabled;
+}
+
+//-------------------------------------------------
+// read
+//-------------------------------------------------
+
+bool dmv_k233_device::read(offs_t offset, UINT8 &data)
+{
+ if (m_enabled && offset >= 0xc000 && offset < 0x10000)
+ {
+ data = m_ram[offset & 0x3fff];
+ return true;
+ }
+
+ return false;
+}
+
+//-------------------------------------------------
+// write
+//-------------------------------------------------
+
+bool dmv_k233_device::write(offs_t offset, UINT8 data)
+{
+ if (m_enabled && offset >= 0xc000 && offset < 0x10000)
+ {
+ m_ram[offset & 0x3fff] = data;
+ return true;
+ }
+
+ return false;
+}