CLK/Components/9918/Implementation/LineLayout.hpp

78 lines
2.7 KiB
C++

//
// LineLayout.hpp
// Clock Signal
//
// Created by Thomas Harte on 18/05/2023.
// Copyright © 2023 Thomas Harte. All rights reserved.
//
#pragma once
namespace TI::TMS {
template <Personality personality, typename Enable = void> struct LineLayout;
// Line layout is:
//
// [0, EndOfSync] sync
// (EndOfSync, StartOfColourBurst] blank
// (StartOfColourBurst, EndOfColourBurst] colour burst
// (EndOfColourBurst, EndOfLeftErase] blank
// (EndOfLeftErase, EndOfLeftBorder] border colour
// (EndOfLeftBorder, EndOfPixels] pixel content
// (EndOfPixels, EndOfRightBorder] border colour
// [EndOfRightBorder, <end of line>] blank
//
// ... with minor caveats:
// * horizontal adjust on the Yamaha VDPs is applied to EndOfLeftBorder and EndOfPixels;
// * the Sega VDPs may programatically extend the left border; and
// * text mode on all VDPs adjusts border width.
template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_classic_vdp(personality)>> {
constexpr static int StartOfSync = 0;
constexpr static int EndOfSync = 26;
constexpr static int StartOfColourBurst = 29;
constexpr static int EndOfColourBurst = 43;
constexpr static int EndOfLeftErase = 50;
constexpr static int EndOfLeftBorder = 63;
constexpr static int EndOfPixels = 319;
constexpr static int EndOfRightBorder = 334;
constexpr static int CyclesPerLine = 342;
constexpr static int TextModeEndOfLeftBorder = 69;
constexpr static int TextModeEndOfPixels = 309;
constexpr static int ModeLatchCycle = 36; // Just a guess; correlates with the known 144 for the Yamaha VDPs,
// and falls into the collection gap between the final sprite
// graphics and the initial tiles or pixels.
/// The number of internal cycles that must elapse between a request to read or write and
/// it becoming a candidate for action.
constexpr static int VRAMAccessDelay = 6;
};
template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_yamaha_vdp(personality)>> {
constexpr static int StartOfSync = 0;
constexpr static int EndOfSync = 100;
constexpr static int StartOfColourBurst = 113;
constexpr static int EndOfColourBurst = 167;
constexpr static int EndOfLeftErase = 202;
constexpr static int EndOfLeftBorder = 258;
constexpr static int EndOfPixels = 1282;
constexpr static int EndOfRightBorder = 1341;
constexpr static int CyclesPerLine = 1368;
constexpr static int TextModeEndOfLeftBorder = 294;
constexpr static int TextModeEndOfPixels = 1254;
constexpr static int ModeLatchCycle = 144;
/// The number of internal cycles that must elapse between a request to read or write and
/// it becoming a candidate for action.
constexpr static int VRAMAccessDelay = 16;
};
}