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Diffstat (limited to 'src/devices/bus/ti99/internal/buffram.h')
-rw-r--r-- | src/devices/bus/ti99/internal/buffram.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/devices/bus/ti99/internal/buffram.h b/src/devices/bus/ti99/internal/buffram.h new file mode 100644 index 00000000000..646716d665b --- /dev/null +++ b/src/devices/bus/ti99/internal/buffram.h @@ -0,0 +1,49 @@ +// license:LGPL-2.1+ +// copyright-holders:Michael Zapf +/******************************************************************************* + + Buffered RAM circuit. + + Michael Zapf + March 2020 + +*******************************************************************************/ + +#ifndef MAME_BUS_TI99_INTERNAL_BRAM_H +#define MAME_BUS_TI99_INTERNAL_BRAM_H + +#pragma once + +namespace bus::ti99::internal { + +// =========== Buffered RAM ================ +class buffered_ram_device : public device_t, public device_nvram_interface +{ +public: + buffered_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock); + buffered_ram_device &set_size(int size) { m_size = size; return *this; } + + // read/write + uint8_t read(offs_t offset) { return m_mem[offset % m_size]; } + void write(offs_t offset, uint8_t data) { m_mem[offset % m_size] = data; } + + void set_buffered(bool on) { nvram_enable_backup(on); } + +private: + virtual void device_start() override; + + // derived class overrides + virtual void nvram_default() override; + virtual bool nvram_read(util::read_stream &file) override; + virtual bool nvram_write(util::write_stream &file) override; + + int m_size; + std::unique_ptr<u8 []> m_mem; +}; + + +} // end namespace bus::ti99::internal + +DECLARE_DEVICE_TYPE_NS(BUFF_RAM, bus::ti99::internal, buffered_ram_device) + +#endif // MAME_BUS_TI99_INTERNAL_BRAM_H |