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author therealmogminer@gmail.com <therealmogminer@gmail.com>2016-10-27 13:46:10 +0200
committer therealmogminer@gmail.com <therealmogminer@gmail.com>2016-10-27 13:46:42 +0200
commit8225a140ee95a2688c6788c947d58909a4659527 (patch)
tree3d33273d239305852b086724bbbff18c41930705 /src/devices/machine/am2847.cpp
parent0d87ff49b17df9995d4556aaea9c5680b446604f (diff)
-hazeltin: Added preliminary video, still broken due to timing issues. [Ryan Holtz]
Diffstat (limited to 'src/devices/machine/am2847.cpp')
-rw-r--r--src/devices/machine/am2847.cpp169
1 files changed, 169 insertions, 0 deletions
diff --git a/src/devices/machine/am2847.cpp b/src/devices/machine/am2847.cpp
new file mode 100644
index 00000000000..ef8954c859e
--- /dev/null
+++ b/src/devices/machine/am2847.cpp
@@ -0,0 +1,169 @@
+// license:BSD-3-Clause
+// copyright-holders:Ryan Holtz
+/**********************************************************************
+
+ AMD Am2847/Am2896 Quad 80/96-Bit Static Shift Registers
+
+**********************************************************************/
+
+#include "am2847.h"
+
+const device_type AM2847 = &device_creator<am2847_device>;
+const device_type AM2849 = &device_creator<am2849_device>;
+const device_type TMS3409 = &device_creator<tms3409_device>;
+
+am2847_base_device::am2847_base_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, uint32_t clock, const char *shortname, size_t size)
+ : device_t(mconfig, type, name, tag, owner, clock, shortname, __FILE__)
+ , m_in(0)
+ , m_out(0)
+ , m_rc(0)
+ , m_cp(0)
+ , m_buffer_size(size)
+{
+}
+
+am2847_device::am2847_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : am2847_base_device(mconfig, AM2847, "AMD Am2847 80-bit Static Shift Register", tag, owner, clock, "am2847", 5)
+{
+}
+
+am2849_device::am2849_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : am2847_base_device(mconfig, AM2849, "AMD Am2849 96-bit Static Shift Register", tag, owner, clock, "am2847", 6)
+{
+}
+
+tms3409_device::tms3409_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : am2847_base_device(mconfig, TMS3409, "TI TMS3409 80-bit Static Shift Register", tag, owner, clock, "am2847", 5)
+{
+}
+
+void am2847_base_device::device_start()
+{
+ for (int bit = 0; bit < 4; bit++)
+ {
+ m_shifters[bit].alloc(m_buffer_size);
+ }
+
+ init();
+
+ save_item(NAME(m_in));
+ save_item(NAME(m_out));
+}
+
+void am2847_base_device::device_reset()
+{
+ init();
+}
+
+void am2847_base_device::init()
+{
+ m_in = 0;
+ m_out = 0;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::in_a_w )
+{
+ m_in &= ~0x01;
+ m_in |= state;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::in_b_w )
+{
+ m_in &= ~0x02;
+ m_in |= state << 1;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::in_c_w )
+{
+ m_in &= ~0x04;
+ m_in |= state << 2;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::in_d_w )
+{
+ m_in &= ~0x08;
+ m_in |= state << 3;
+}
+
+void am2847_base_device::in_w(uint8_t data)
+{
+ m_in = data & 0x0f;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::rc_a_w )
+{
+ m_rc &= ~0x01;
+ m_rc |= state;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::rc_b_w )
+{
+ m_rc &= ~0x02;
+ m_rc |= state << 1;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::rc_c_w )
+{
+ m_rc &= ~0x04;
+ m_rc |= state << 2;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::rc_d_w )
+{
+ m_rc &= ~0x08;
+ m_rc |= state << 3;
+}
+
+void am2847_base_device::rc_w(uint8_t data)
+{
+ m_rc = data & 0x0f;
+}
+
+WRITE_LINE_MEMBER( am2847_base_device::cp_w )
+{
+ if (m_cp != state && state != 0)
+ {
+ shift();
+ }
+ m_cp = state;
+}
+
+void am2847_base_device::shift()
+{
+ for (int bit = 0; bit < 4; bit++)
+ {
+ m_out &= ~(1 << bit);
+ m_out |= m_shifters[bit].shift(BIT(m_rc, bit) != 0, BIT(m_in, bit)) << bit;
+ }
+}
+
+void am2847_base_device::shifter::alloc(size_t size)
+{
+ m_buffer_size = size;
+ m_buffer = std::make_unique<uint16_t[]>(m_buffer_size);
+ init();
+}
+
+void am2847_base_device::shifter::init()
+{
+ memset(&m_buffer[0], 0, m_buffer_size * 2);
+}
+
+int am2847_base_device::shifter::shift(bool recycle, int in)
+{
+ int out = m_buffer[m_buffer_size-1] & 1;
+ for (int word = m_buffer_size - 1; word >= 1; word--)
+ {
+ m_buffer[word] >>= 1;
+ m_buffer[word] |= (m_buffer[word - 1] & 1) << 15;
+ }
+
+ m_buffer[0] >>= 1;
+
+ if (recycle)
+ m_buffer[0] |= out << 15;
+ else
+ m_buffer[0] |= (in & 1) << 15;
+
+ return out;
+}