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author | 2015-11-08 12:56:12 +0100 | |
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committer | 2015-11-08 12:56:12 +0100 | |
commit | 7c19aac60e12d6f5ea301bdb34d7826a01e0b06f (patch) | |
tree | f310d86aa2c6bfc19d115307dedde4eb0cd52dad /src/devices/bus/generic/ram.cpp | |
parent | a57b46ae933badd7441ce1644711dbb851e2b504 (diff) |
Rename *.c -> *.cpp in our source (nw)
Diffstat (limited to 'src/devices/bus/generic/ram.cpp')
-rw-r--r-- | src/devices/bus/generic/ram.cpp | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/devices/bus/generic/ram.cpp b/src/devices/bus/generic/ram.cpp new file mode 100644 index 00000000000..3767ddae724 --- /dev/null +++ b/src/devices/bus/generic/ram.cpp @@ -0,0 +1,123 @@ +// license:BSD-3-Clause +// copyright-holders:Fabio Priuli +/*********************************************************************************************************** + + + Generic RAM socket emulation + + This offers generic access to RAM + + generic_ram_plain : returns 0xff when the system reads beyond the end of the RAM + generic_ram_linear : maps linearly the RAM in the accessed area (i.e., read/write offset is masked with + (RAM size - 1) ) + + TODO: + - support variable RAM size + - possibly support linear mapping when non-power of 2 RAMs are mapped + - add support for 16bit & 32bit RAM access + + ***********************************************************************************************************/ + + +#include "emu.h" +#include "ram.h" + +//------------------------------------------------- +// constructor +//------------------------------------------------- + +const device_type GENERIC_RAM_32K_PLAIN = &device_creator<generic_ram_32k_plain_device>; +const device_type GENERIC_RAM_64K_PLAIN = &device_creator<generic_ram_64k_plain_device>; +const device_type GENERIC_RAM_128K_PLAIN = &device_creator<generic_ram_128k_plain_device>; +const device_type GENERIC_RAM_32K_LINEAR = &device_creator<generic_ram_32k_linear_device>; +const device_type GENERIC_RAM_64K_LINEAR = &device_creator<generic_ram_64k_linear_device>; +const device_type GENERIC_RAM_128K_LINEAR = &device_creator<generic_ram_128k_linear_device>; + + +generic_ram_plain_device::generic_ram_plain_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, UINT32 size, const char *shortname, const char *source) + : device_t(mconfig, type, name, tag, owner, clock, shortname, source), + device_generic_cart_interface(mconfig, *this), + m_size(size) +{ +} + +generic_ram_linear_device::generic_ram_linear_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, UINT32 size, const char *shortname, const char *source) + : device_t(mconfig, type, name, tag, owner, clock, shortname, source), + device_generic_cart_interface(mconfig, *this), + m_size(size) +{ +} + + +generic_ram_32k_plain_device::generic_ram_32k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_plain_device(mconfig, GENERIC_RAM_32K_PLAIN, "Generic RAM 32K (plain mapping)", tag, owner, clock, 0x8000, "generic_ram32p", __FILE__) +{ +} + +generic_ram_64k_plain_device::generic_ram_64k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_plain_device(mconfig, GENERIC_RAM_64K_PLAIN, "Generic RAM 64K (plain mapping)", tag, owner, clock, 0x10000, "generic_ram64p", __FILE__) +{ +} + +generic_ram_128k_plain_device::generic_ram_128k_plain_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_plain_device(mconfig, GENERIC_RAM_128K_PLAIN, "Generic RAM 128K (plain mapping)", tag, owner, clock, 0x20000, "generic_ram128p", __FILE__) +{ +} + +generic_ram_32k_linear_device::generic_ram_32k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_linear_device(mconfig, GENERIC_RAM_32K_LINEAR, "Generic RAM 32K (linear mapping)", tag, owner, clock, 0x8000, "generic_ram32l", __FILE__) +{ +} + +generic_ram_64k_linear_device::generic_ram_64k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_linear_device(mconfig, GENERIC_RAM_64K_LINEAR, "Generic RAM 64K (linear mapping)", tag, owner, clock, 0x10000, "generic_ram64l", __FILE__) +{ +} + +generic_ram_128k_linear_device::generic_ram_128k_linear_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : generic_ram_linear_device(mconfig, GENERIC_RAM_128K_LINEAR, "Generic RAM 128K (linear mapping)", tag, owner, clock, 0x20000, "generic_ram128l", __FILE__) +{ +} + + +void generic_ram_plain_device::device_start() +{ + m_ram.resize(m_size); + save_item(NAME(m_ram)); +} + +void generic_ram_linear_device::device_start() +{ + m_ram.resize(m_size); + save_item(NAME(m_ram)); +} + + +/*------------------------------------------------- + mapper specific handlers + -------------------------------------------------*/ + +READ8_MEMBER(generic_ram_plain_device::read_ram) +{ + if (offset < m_ram.size()) + return m_ram[offset]; + else + return 0xff; +} + +WRITE8_MEMBER(generic_ram_plain_device::write_ram) +{ + if (offset < m_ram.size()) + m_ram[offset] = data; +} + + +READ8_MEMBER(generic_ram_linear_device::read_ram) +{ + return m_ram[offset % m_ram.size()]; +} + +WRITE8_MEMBER(generic_ram_linear_device::write_ram) +{ + m_ram[offset % m_ram.size()] = data; +} |