6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-08-08 14:25:05 +00:00
Code Issues Projects Releases Wiki Activity

Implement much of Yamaha line interrupts.

Browse Source
This commit is contained in:
Thomas Harte
2023-01-30 21:24:53 -05:00
parent 30a2b1611f
commit 492a170b20
1 changed files with 25 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
Components/9918/Implementation/9918.cpp
View File

@@ -37,6 +37,11 @@ Base<personality>::Base() :
mode_timing_.end_of_frame_interrupt_position.row = 193; mode_timing_.end_of_frame_interrupt_position.row = 193;
} }
if constexpr (is_yamaha_vdp(personality)) {
// TODO: start of sync, or end of sync?
mode_timing_.line_interrupt_position = Timing<personality>::StartOfSync;
}
// Establish that output is delayed after reading by `output_lag` cycles; start // Establish that output is delayed after reading by `output_lag` cycles; start
// at a random position. // at a random position.
fetch_pointer_.row = rand() % 262; fetch_pointer_.row = rand() % 262;
@@ -255,6 +260,12 @@ void TMS9918<personality>::run_for(const HalfCycles cycles) {
} }
} }
if constexpr (is_yamaha_vdp(personality)) {
if(this->fetch_pointer_.row == this->line_interrupt_target_) {
this->line_interrupt_pending_ = true;
}
}
// TODO: the V9938 provides line interrupts from direct specification of the target line. // TODO: the V9938 provides line interrupts from direct specification of the target line.
// So life is easy. // So life is easy.
} }
@@ -723,6 +734,7 @@ void Base<personality>::commit_register(int reg, uint8_t value) {
(Storage<personality>::mode_ & 3) | (Storage<personality>::mode_ & 3) |
((value & 0xe) << 1) ((value & 0xe) << 1)
); );
enable_line_interrupts_ = value & 0x10;
LOG("TODO: Yamaha additional mode selection; " << PADHEX(2) << +value); LOG("TODO: Yamaha additional mode selection; " << PADHEX(2) << +value);
// b1–b3: M3–M5 // b1–b3: M3–M5
@@ -819,7 +831,7 @@ void Base<personality>::commit_register(int reg, uint8_t value) {
break; break;
case 19: case 19:
LOG("TODO: Yamaha interrupt line; " << PADHEX(2) << +value); line_interrupt_target_ = value;
// b0–b7: line to match for interrupts (if eabled) // b0–b7: line to match for interrupts (if eabled)
break; break;
@@ -1020,16 +1032,20 @@ uint8_t Base<personality>::read_register() {
default: default:
case 0: break; case 0: break;
case 1: case 1: {
// b7 = light pen; set when light is detected, reset on read; // b7 = light pen; set when light is detected, reset on read;
// or: mouse button 2 currently down. // or: mouse button 2 currently down.
// b6 = light pen button or mouse button 1. // b6 = light pen button or mouse button 1.
// b5–b1 = VDP identification (1 = 9938; 2 = 9958) // b5–b1 = VDP identification (1 = 9938; 2 = 9958)
// b0 = set when the VDP reaches the line provided in the line interrupt register. // b0 = set when the VDP reaches the line provided in the line interrupt register.
// Reset upon read. // Reset upon read.
return const uint8_t result =
personality == Personality::V9938 ? 0x2 : 0x4; (personality == Personality::V9938 ? 0x2 : 0x4) |
break; (line_interrupt_pending_ ? 0x01 : 0x00);
line_interrupt_pending_ = false;
return result;
} break;
case 2: { case 2: {
// b7 = transfer ready flag (i.e. VDP ready for next transfer) // b7 = transfer ready flag (i.e. VDP ready for next transfer)
@@ -1189,6 +1205,10 @@ HalfCycles TMS9918<personality>::get_next_sequence_point() const {
} }
} }
if constexpr (is_yamaha_vdp(personality)) {
// TODO: time to next retrace interrupt.
}
// If there's actually no interrupt upcoming, despite being enabled, either return // If there's actually no interrupt upcoming, despite being enabled, either return
// the frame end interrupt or no interrupt pending as appropriate. // the frame end interrupt or no interrupt pending as appropriate.
if(next_line_interrupt_row == -1) { if(next_line_interrupt_row == -1) {