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Diffstat (limited to 'src/devices/cpu/pps41/mm75op.cpp')
-rw-r--r--src/devices/cpu/pps41/mm75op.cpp40
1 files changed, 40 insertions, 0 deletions
diff --git a/src/devices/cpu/pps41/mm75op.cpp b/src/devices/cpu/pps41/mm75op.cpp
new file mode 100644
index 00000000000..445655ef31b
--- /dev/null
+++ b/src/devices/cpu/pps41/mm75op.cpp
@@ -0,0 +1,40 @@
+// license:BSD-3-Clause
+// copyright-holders:hap
+
+// MM75 opcode handlers
+
+#include "emu.h"
+#include "mm75.h"
+
+
+// unsupported opcodes
+
+void mm75_device::op_ios()
+{
+ // IOS: does not have serial I/O
+ op_illegal();
+}
+
+void mm75_device::op_i2c()
+{
+ // I2C: does not have PI5-8 pins
+ m_a = 0;
+ op_illegal();
+}
+
+
+// changed opcodes
+
+void mm75_device::op_ibm()
+{
+ // IBM: INT1 is shared with RIO8
+ mm76_device::op_ibm();
+ m_a &= ~(m_int_line[1] << 3);
+}
+
+void mm75_device::op_int1h()
+{
+ // INT1H: INT1 is shared with RIO8
+ int state = (m_read_r() & m_r_output) >> 7 & m_int_line[1];
+ m_skip = bool(state);
+}