diff options
Diffstat (limited to 'src/devices/cpu/m6502/r65c19.cpp')
-rw-r--r-- | src/devices/cpu/m6502/r65c19.cpp | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/devices/cpu/m6502/r65c19.cpp b/src/devices/cpu/m6502/r65c19.cpp new file mode 100644 index 00000000000..ffd6c3ee2db --- /dev/null +++ b/src/devices/cpu/m6502/r65c19.cpp @@ -0,0 +1,290 @@ +// license:BSD-3-Clause +// copyright-holders:AJR +/********************************************************************** + + Rockwell R65C19 Microcomputer (MCU) + + TODO: fully describe this MCU and its successors (C29, C39) and + emulate their internal peripherals (only core emulation now) + +**********************************************************************/ + +#include "emu.h" +#include "r65c19.h" +#include "r65c19d.h" + +DEFINE_DEVICE_TYPE(R65C19, r65c19_device, "r65c19", "Rockwell R65C19 MCU") +DEFINE_DEVICE_TYPE(L2800, l2800_device, "l2800", "Rockwell L2800 MCU") + +r65c19_device::r65c19_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock, address_map_constructor internal_map) + : r65c02_device(mconfig, type, tag, owner, clock) + , m_w(0) + , m_i(0) + , m_page1_ram(*this, "page1") + , m_cir(0) +{ + program_config.m_internal_map = std::move(internal_map); +} + +r65c19_device::r65c19_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : r65c19_device(mconfig, R65C19, tag, owner, clock, address_map_constructor()) +{ +} + +c39_device::c39_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock, address_map_constructor internal_map) + : r65c19_device(mconfig, type, tag, owner, clock, internal_map) + , m_exp_config("expansion", ENDIANNESS_LITTLE, 8, 21, 0) + , m_es4_config("es4", ENDIANNESS_LITTLE, 8, 9, 0) +{ +} + +l2800_device::l2800_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : c39_device(mconfig, L2800, tag, owner, clock, address_map_constructor(FUNC(l2800_device::internal_map), this)) +{ +} + +std::unique_ptr<util::disasm_interface> r65c19_device::create_disassembler() +{ + return std::make_unique<r65c19_disassembler>(); +} + +void r65c19_device::do_add(u8 v) +{ + P &= ~F_C; + do_adc(v); +} + +u16 r65c19_device::do_accumulate(u16 v, u16 w) +{ + // Compute the sum + s32 result = s16(v) + s16(w); + + // Determine flags and saturate result upon overflow + P &= ~(F_N | F_V); + if (result > 32767) + { + P |= F_V; + result = 32767; + } + else if (result < 0) + { + P |= F_N; + if (result < -32768) + { + P |= F_V; + result = -32768; + } + } + + // MPA and MPY always destroy the old value of Y, as does RND when it overflows + Y = result & 0xff; + + // 16-bit result to W, or high byte to A + return result & 0xffff; +} + +u16 r65c19_device::get_irq_vector() +{ + // TODO: this is a stub + return 0xfffc; +} + +void r65c19_device::device_start() +{ + mintf = std::make_unique<mi_default>(); + + c19_init(); +} + +device_memory_interface::space_config_vector c39_device::memory_space_config() const +{ + return space_config_vector { + std::make_pair(AS_PROGRAM, &program_config), + std::make_pair(AS_DATA, &m_exp_config), + std::make_pair(AS_IO, &m_es4_config) + }; +} + +void c39_device::device_start() +{ + std::unique_ptr<mi_banked> intf = std::make_unique<mi_banked>(); + space(AS_DATA).cache(intf->escache); + space(AS_DATA).specific(intf->exp); + space(AS_IO).specific(intf->es4); + + save_item(NAME(intf->bsr)); + save_item(NAME(intf->pbs)); + mintf = std::move(intf); + + c19_init(); + + for (int i = 0; i < 8; i++) + state_add(C39_BSR0 + i, string_format("BSR%d", i).c_str(), downcast<mi_banked &>(*mintf).bsr[i]); +} + +void r65c19_device::c19_init() +{ + init(); + + state_add(R65C19_W, "W", m_w); + state_add<u8>(R65C19_WL, "WL", + [this]() { return m_w & 0xff; }, + [this](u8 data) { m_w = set_l(m_w, data); }).noshow(); + state_add<u8>(R65C19_WH, "WH", + [this]() { return m_w >> 8; }, + [this](u8 data) { m_w = set_h(m_w, data); }).noshow(); + state_add(R65C19_I, "I", m_i); + + save_item(NAME(m_w)); + save_item(NAME(m_i)); + save_item(NAME(m_cir)); +} + +void r65c19_device::device_reset() +{ + r65c02_device::device_reset(); + + m_cir = 0x00; +} + +void c39_device::device_reset() +{ + r65c02_device::device_reset(); + + mi_banked &intf = downcast<mi_banked &>(*mintf); + intf.bsr[0] = 0xe0; + intf.bsr[1] = 0xd1; + intf.bsr[2] = 0xb2; + intf.bsr[3] = 0xb3; + intf.bsr[4] = 0x74; + intf.bsr[5] = 0x75; + intf.bsr[6] = 0x76; + intf.bsr[7] = 0x77; + intf.pbs = 0xff; +} + +u8 r65c19_device::page1_seg_r(offs_t offset) +{ + return m_page1_ram[(m_cir & 0x03) << 6 | offset]; +} + +void r65c19_device::page1_seg_w(offs_t offset, u8 data) +{ + m_page1_ram[(m_cir & 0x03) << 6 | offset] = data; +} + +u8 r65c19_device::cir_r() +{ + return m_cir; +} + +void r65c19_device::cir_w(u8 data) +{ + // TODO: clear interrupts + m_cir = data & 0x07; +} + +u8 c39_device::mi_banked::exp_read(u16 adr) +{ + return exp.read_byte(u32(bsr[(adr & 0xe000) >> 13]) << 13 | (adr & 0x1fff)); +} + +u8 c39_device::mi_banked::exp_read_cached(u16 adr) +{ + return escache.read_byte(u32(bsr[(adr & 0xe000) >> 13]) << 13 | (adr & 0x1fff)); +} + +void c39_device::mi_banked::exp_write(u16 adr, u8 val) +{ + exp.write_byte(u32(bsr[(adr & 0xe000) >> 13]) << 13 | (adr & 0x1fff), val); +} + +u8 c39_device::mi_banked::es4_read(u16 adr) +{ + return es4.read_byte(adr & 0x1ff); +} + +void c39_device::mi_banked::es4_write(u16 adr, u8 val) +{ + es4.write_byte(adr & 0x1ff, val); +} + +u8 c39_device::mi_banked::read(u16 adr) +{ + return program.read_byte(adr); +} + +u8 c39_device::mi_banked::read_sync(u16 adr) +{ + if (adr < 0x0600) + return cprogram.read_byte(adr); + else if (adr >= 0x0800 || BIT(pbs, 1)) + return exp_read_cached(adr); + else + return es4_read(adr); +} + +u8 c39_device::mi_banked::read_arg(u16 adr) +{ + if (adr < 0x0600) + return cprogram.read_byte(adr); + else if (adr >= 0x0800 || BIT(pbs, 1)) + return exp_read_cached(adr); + else + return es4_read(adr); +} + +void c39_device::mi_banked::write(u16 adr, u8 val) +{ + program.write_byte(adr, val); +} + +u8 c39_device::pbs_r() +{ + return downcast<mi_banked &>(*mintf).pbs; +} + +void c39_device::pbs_w(u8 data) +{ + downcast<mi_banked &>(*mintf).pbs = data; +} + +u8 c39_device::bsr_r(offs_t offset) +{ + return downcast<mi_banked &>(*mintf).bsr[offset]; +} + +void c39_device::bsr_w(offs_t offset, u8 data) +{ + downcast<mi_banked &>(*mintf).bsr[offset] = data; +} + +u8 c39_device::expansion_r(offs_t offset) +{ + mi_banked &intf = downcast<mi_banked &>(*mintf); + if (offset >= 0x0200 || BIT(intf.pbs, 1)) + return intf.exp_read(offset + 0x0600); + else + return intf.es4_read(offset + 0x0600); +} + +void c39_device::expansion_w(offs_t offset, u8 data) +{ + mi_banked &intf = downcast<mi_banked &>(*mintf); + if (offset >= 0x0200 || BIT(intf.pbs, 1)) + intf.exp_write(offset + 0x0600, data); + else + intf.es4_write(offset + 0x0600, data); +} + +void l2800_device::internal_map(address_map &map) +{ + // TODO: most registers still unimplemented + map(0x0005, 0x0005).rw(FUNC(l2800_device::pbs_r), FUNC(l2800_device::pbs_w)); + map(0x000b, 0x000b).rw(FUNC(l2800_device::cir_r), FUNC(l2800_device::cir_w)); + map(0x0018, 0x001f).rw(FUNC(l2800_device::bsr_r), FUNC(l2800_device::bsr_w)); + map(0x0040, 0x05fd).ram(); // Page 0 has 192 dedicated bytes here + map(0x0600, 0xffff).rw(FUNC(l2800_device::expansion_r), FUNC(l2800_device::expansion_w)); +} + +#include "cpu/m6502/r65c19.hxx" |