From 3544746934777de2f320724d4ee96eb1c1856af2 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Tue, 27 Jul 2021 16:41:18 -0400 Subject: [PATCH] Modifies interface, starts on scheduler. Probably corrects the pixel clock, which I think was scaled up by a factor of 4. --- Machines/Amiga/Amiga.cpp | 2 +- Machines/Amiga/Chipset.cpp | 98 +++++++++++++++++++++++++++++--------- Machines/Amiga/Chipset.hpp | 21 +++++--- 3 files changed, 91 insertions(+), 30 deletions(-) diff --git a/Machines/Amiga/Amiga.cpp b/Machines/Amiga/Amiga.cpp index c7871d273..35759f674 100644 --- a/Machines/Amiga/Amiga.cpp +++ b/Machines/Amiga/Amiga.cpp @@ -79,7 +79,7 @@ class ConcreteMachine: cia_b_.run_for(e_clocks); } - const auto changes = chipset_.run_for(cycle.length, false); + const auto changes = chipset_.run_for(cycle.length); cia_a_.advance_tod(changes.vsyncs); cia_b_.advance_tod(changes.hsyncs); mc68000_.set_interrupt_level(changes.interrupt_level); diff --git a/Machines/Amiga/Chipset.cpp b/Machines/Amiga/Chipset.cpp index 32021906d..1f7ffc78b 100644 --- a/Machines/Amiga/Chipset.cpp +++ b/Machines/Amiga/Chipset.cpp @@ -42,20 +42,75 @@ Chipset::Chipset(uint16_t *ram, size_t size) : crt_(908, 4, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red4Green4Blue4) { } -Chipset::Changes Chipset::run_for(HalfCycles length, bool) { +Chipset::Changes Chipset::run_for(HalfCycles length) { + return run(length); +} + +Chipset::Changes Chipset::run_until_cpu_slot() { + return run(); +} + +template bool Chipset::perform_cycle() { + // TODO: actual CPU scheduling. + if constexpr (stop_if_cpu) { + return true; + } + + return false; +} + +template Chipset::Changes Chipset::run(HalfCycles length) { Changes changes; + // This code uses 'pixels' as a measure, which is equivalent to one pixel clock time, + // or half a cycle. auto pixels_remaining = length.as(); - // TODO: all DMA scheduling and actions, possibly stopping upon discovery of a CPU slot. - // Video memory collected here is spirited away for unspooling in the next loop. - // Update raster position, spooling out graphics. while(pixels_remaining) { // Determine number of pixels left on this line. - int line_pixels = std::min(pixels_remaining, line_length_ - x_); + int line_pixels = std::min(pixels_remaining, line_length_ - line_cycle_); pixels_remaining -= line_pixels; + // + // Run DMA scheduler. + // + + int final_slot = (line_cycle_ + line_pixels) >> 2; + + if((line_cycle_ >> 2) == final_slot) { + // Not enough pixels left to fill any whole slots, just stop. + break; + } + +#define C(x) \ + case x: \ + if constexpr(stop_on_cpu) { if(perform_cycle()) break; } else { perform_cycle(); } \ + line_cycle_ += 4; \ + if((line_cycle_ >> 2) == final_slot) break; + +#define C10(x) C(x); C(x+1); C(x+2); C(x+3); C(x+4); C(x+5); C(x+6); C(x+7); C(x+8); C(x+9); + switch(line_cycle_ >> 2) { + C10(0); C10(10); C10(20); C10(30); C10(40); + C10(50); C10(60); C10(70); C10(80); C10(90); + C10(100); C10(110); C10(120); C10(130); C10(140); + C10(150); C10(160); C10(170); C10(180); C10(190); + C10(200); C10(210); + C(220); C(221); C(222); C(223); C(224); + C(225); C(226); C(227); C(228); + + default: assert(false); + } +#undef C + + // Update per the possibility that the above ended early. + final_slot = line_cycle_ >> 2; + int slot = line_cycle_ >> 2; + + // + // Output video signal as implied by whatever happened above. + // + // Hardware stop is at 0x18; // 12/64 * 227 = 42.5625 // @@ -79,11 +134,10 @@ Chipset::Changes Chipset::run_for(HalfCycles length, bool) { static_assert(blank3 == 43); #define LINK(location, action, length) \ - if(x_ < (location) && final_x >= (location)) { \ + if(slot < (location) && final_slot >= (location)) { \ crt_.action((length) * 4); \ } - const int final_x = x_ + line_pixels; if(y_ < vertical_blank_height_) { // Put three lines of sync at the centre of the vertical blank period. // TODO: offset by half a line if interlaced and on an odd frame. @@ -124,34 +178,23 @@ Chipset::Changes Chipset::run_for(HalfCycles length, bool) { LINK(burst, output_default_colour_burst, burst - blank2); // TODO: only if colour enabled. LINK(blank3, output_blank, blank3 - burst); -// if(final_x > blank3) { -// const int start_x = std::max(blank3, x_); -// -// uint16_t *const pixels = reinterpret_cast(crt_.begin_data(2)); -// if(pixels) { -// *pixels = palette_[0]; -// } -// crt_.output_data((final_x - start_x) * 4, 1); -// } - // Output colour 0 to fill the rest of the line; Kickstart uses this // colour to post the error code. TODO: actual pixels, etc. - if(final_x == line_length_) { + if(line_cycle_ >= line_length_) { uint16_t *const pixels = reinterpret_cast(crt_.begin_data(1)); if(pixels) { *pixels = palette_[0]; } - crt_.output_data((final_x - blank3) * 4, 1); + crt_.output_data(line_length_ - blank3 * 4, 1); } } // Advance intraline counter and possibly ripple upwards into // lines and fields. - x_ += line_pixels; - if(x_ == line_length_) { + if(line_cycle_ >= line_length_) { ++changes.hsyncs; - x_ = 0; + line_cycle_ = 0; ++y_; if(y_ == frame_height_) { @@ -160,6 +203,9 @@ Chipset::Changes Chipset::run_for(HalfCycles length, bool) { update_interrupts(); y_ = 0; + + // TODO: the manual is vague on when this happens. Try to find out. + copper_address_ = copper_addresses_[0]; } } } @@ -221,7 +267,7 @@ void Chipset::perform(const CPU::MC68000::Microcycle &cycle) { cycle.set_value16(position); } break; case Read(0x006): { - const uint16_t position = uint16_t((x_ << 8) | (y_ & 0xff)); + const uint16_t position = uint16_t(((line_cycle_ << 6) & 0xff00) | (y_ & 0x00ff)); LOG("Read position low " << PADHEX(4) << position); cycle.set_value16(position); } break; @@ -395,21 +441,27 @@ void Chipset::perform(const CPU::MC68000::Microcycle &cycle) { break; case Write(0x080): LOG("TODO: coprocessor first location register high " << PADHEX(4) << cycle.value16()); + copper_addresses_[0] = (copper_addresses_[0] & 0x0000'ffff) | uint32_t(cycle.value16() << 16); break; case Write(0x082): LOG("TODO: coprocessor first location register low " << PADHEX(4) << cycle.value16()); + copper_addresses_[0] = (copper_addresses_[0] & 0xffff'0000) | uint32_t(cycle.value16() << 0); break; case Write(0x084): LOG("TODO: coprocessor second location register high " << PADHEX(4) << cycle.value16()); + copper_addresses_[1] = (copper_addresses_[1] & 0x0000'ffff) | uint32_t(cycle.value16() << 16); break; case Write(0x086): LOG("TODO: coprocessor second location register low " << PADHEX(4) << cycle.value16()); + copper_addresses_[1] = (copper_addresses_[1] & 0xffff'0000) | uint32_t(cycle.value16() << 0); break; case Write(0x088): case Read(0x088): LOG("TODO: coprocessor restart at first location"); + copper_address_ = copper_addresses_[0]; break; case Write(0x08a): case Read(0x08a): LOG("TODO: coprocessor restart at second location"); + copper_address_ = copper_addresses_[1]; break; case Write(0x08c): LOG("TODO: coprocessor instruction fetch identity " << PADHEX(4) << cycle.value16()); diff --git a/Machines/Amiga/Chipset.hpp b/Machines/Amiga/Chipset.hpp index 9128fdb82..8b009bcc3 100644 --- a/Machines/Amiga/Chipset.hpp +++ b/Machines/Amiga/Chipset.hpp @@ -34,8 +34,11 @@ class Chipset { HalfCycles duration; }; - /// Advances the stated amount of time, possibly stopping if a CPU slot is found. - Changes run_for(HalfCycles, bool stop_on_cpu_slot); + /// Advances the stated amount of time. + Changes run_for(HalfCycles); + + /// Advances to the next available CPU slot. + Changes run_until_cpu_slot(); /// Performs the provided microcycle, which the caller guarantees to be a memory access. void perform(const CPU::MC68000::Microcycle &); @@ -61,7 +64,12 @@ class Chipset { void update_interrupts(); - // MARK: - DMA Control and Blitter. + // MARK: - Scheduler. + + template Changes run(HalfCycles duration = HalfCycles()); + template bool perform_cycle(); + + // MARK: - DMA Control, Scheduler and Blitter. uint16_t dma_control_ = 0; Blitter blitter_; @@ -77,8 +85,8 @@ class Chipset { // MARK: - Raster. - int x_ = 0, y_ = 0; - int line_length_ = 227; + int line_cycle_ = 0, y_ = 0; + int line_length_ = 227 * 4; int frame_height_ = 312; int vertical_blank_height_ = 29; @@ -88,7 +96,8 @@ class Chipset { // MARK: - Copper. - uint16_t copper_address_ = 0; + uint32_t copper_address_ = 0; + uint32_t copper_addresses_[2]{}; // MARK: - Pixel output.