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author | 2016-10-27 13:46:10 +0200 | |
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committer | 2016-10-27 13:46:42 +0200 | |
commit | 8225a140ee95a2688c6788c947d58909a4659527 (patch) | |
tree | 3d33273d239305852b086724bbbff18c41930705 /src/devices/machine/am2847.cpp | |
parent | 0d87ff49b17df9995d4556aaea9c5680b446604f (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.cpp | 169 |
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; +} |