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Starts to make some effort at timers.

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This commit is contained in:
Thomas Harte 2021-02-06 21:02:44 -05:00
parent 819e9039ab
commit acfab1dfb3
4 changed files with 78 additions and 15 deletions
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73
InstructionSets/M50740/Executor.cpp
View File

@ -68,8 +68,6 @@ uint8_t Executor::read(uint16_t address) {
// printf("??? [ff]\n");
return 0xff;
// TODO: external IO ports.
// "Port R"; sixteen four-bit ports
case 0xd0: case 0xd1: case 0xd2: case 0xd3: case 0xd4: case 0xd5: case 0xd6: case 0xd7:
case 0xd8: case 0xd9: case 0xda: case 0xdb: case 0xdc: case 0xdd: case 0xde: case 0xdf:
@ -83,23 +81,23 @@ uint8_t Executor::read(uint16_t address) {
const int port = port_remap[(address - 0xe0) >> 1];
const uint8_t input = port_handler_.get_port_input(port);
// printf("P%d %02x\n", port, (input &~ port_directions_[port]) | (port_outputs_[port] & port_directions_[port]));
// In the direction registers, a 0 indicates input, a 1 indicates output.
return (input &~ port_directions_[port]) | (port_outputs_[port] & port_directions_[port]);
}
case 0xe1: case 0xe3:
case 0xe5: case 0xe9:
// printf("TODO: Ports P0–P3 direction [r %04x]\n", address);
// printf("dir%d %02x\n", port_remap[(address - 0xe0) >> 1], port_directions_[port_remap[(address - 0xe0) >> 1]]);
return port_directions_[port_remap[(address - 0xe0) >> 1]];
// Timers.
case 0xf9: case 0xfa: case 0xfb: case 0xfc: case 0xfd: case 0xfe: case 0xff:
// printf("TODO: Timers [r %04x]\n", address);
// printf("T?? [ff]\n");
return 0xff;
case 0xf9: return prescalers_[0].value;
case 0xfa: return timers_[0].value;
case 0xfb: return timers_[1].value;
case 0xfc: return prescalers_[1].value;
case 0xfd: return timers_[2].value;
case 0xfe: return interrupt_control_;
case 0xff: return timer_control_;
}
}
@ -138,9 +136,14 @@ void Executor::write(uint16_t address, uint8_t value) {
break;
// Timers.
case 0xf9: case 0xfa: case 0xfb: case 0xfc: case 0xfd: case 0xfe: case 0xff:
// printf("TODO: Timers [w %04x %02x]\n", address, value);
break;
case 0xf9: prescalers_[0].reload_value = value; break;
case 0xfa: timers_[0].reload_value = value; break;
case 0xfb: timers_[1].reload_value = value; break;
case 0xfc: prescalers_[1].reload_value = value; break;
case 0xfd: timers_[2].reload_value = value; break;
case 0xfe: interrupt_control_ = value; break;
case 0xff: timer_control_ = value; break;
}
}
@ -184,8 +187,21 @@ template<bool is_brk> inline void Executor::perform_interrupt() {
set_program_counter(uint16_t(memory_[0x1ff4] | (memory_[0x1ff5] << 8)));
}
bool log_print = false;
template <Operation operation, AddressingMode addressing_mode> void Executor::perform() {
// printf("%04x\t[a:%02x x:%02x y:%02x p:%02x s:%02x]\n", program_counter_ & 0x1fff, a_, x_, y_, flags(), s_);
// log_print |= (program_counter_&0x1fff) == 0x106c;
// log_print &= (program_counter_&0x1fff) != 0x1015;
if((program_counter_&0x1fff) == 0x1f24) {
printf("\n");
}
if((program_counter_&0x1fff) == 0x1f33) {
printf("");
}
if(log_print) {
printf("%04x\t[a:%02x x:%02x y:%02x p:%02x s:%02x]\n", program_counter_ & 0x1fff, a_, x_, y_, flags(), s_);
}
// printf("%04x")
// printf("%04x\t%02x\t%d %d\t[a:%02x x:%02x y:%02x p:%02x s:%02x]\t(%s)\n", program_counter_ & 0x1fff, memory_[program_counter_ & 0x1fff], int(operation), int(addressing_mode), a_, x_, y_, flags(), s_, __PRETTY_FUNCTION__ );
@ -741,6 +757,35 @@ template <Operation operation> void Executor::perform(uint8_t *operand [[maybe_u
}
inline void Executor::subtract_duration(int duration) {
// Update count for potential port accesses.
cycles_since_port_handler_ += Cycles(duration);
// Update timer 1/2 prescaler.
constexpr int t12_divider = 1; // TODO: should be 4, I think.
timer_divider_ += duration;
const int t12_ticks = update_timer(prescalers_[0], timer_divider_ / t12_divider);
timer_divider_ &= (t12_divider-1);
// Update timers 1 and 2. TODO: interrupts (elsewhere).
if(update_timer(timers_[0], t12_ticks)) interrupt_control_ |= 0x20;
if(update_timer(timers_[1], t12_ticks)) interrupt_control_ |= 0x08;
// TODO: timer X.
// update_timer(timers_[2], update_timer(prescalers_[1], duration));
// Pass along.
CachingExecutor::subtract_duration(duration);
}
inline int Executor::update_timer(Timer &timer, int count) {
int next_value = timer.value - count;
if(next_value < 0) {
// Determine how many reloads were required to get above zero.
const int reload_value = timer.reload_value ? timer.reload_value : 256;
const int underflow_count = 1 + (-next_value) / reload_value;
timer.value = uint8_t((next_value % reload_value) + timer.reload_value);
return underflow_count;
}
timer.value = uint8_t(next_value);
return 0;
}

13
InstructionSets/M50740/Executor.hpp
View File

@ -136,9 +136,22 @@ class Executor: public CachingExecutor {
bool index_mode_ = false;
bool decimal_mode_ = false;
// IO ports.
uint8_t port_directions_[4] = {0xff, 0xff, 0xff, 0xff};
uint8_t port_outputs_[4] = {0xff, 0xff, 0xff, 0xff};
// Timers.
struct Timer {
uint8_t value = 0, reload_value = 0;
};
int timer_divider_ = 0;
Timer timers_[3], prescalers_[2];
inline int update_timer(Timer &timer, int count);
// Interrupt and timer control.
uint8_t interrupt_control_ = 0, timer_control_ = 0;
// Access helpers.
inline uint8_t read(uint16_t address);
inline void write(uint16_t address, uint8_t value);
inline void push(uint8_t value);

5
Machines/Apple/AppleIIgs/ADB.cpp
View File

@ -175,6 +175,7 @@ void GLU::set_port_output(int port, uint8_t value) {
const bool new_adb_level = !(value & 0x08);
if(new_adb_level != adb_level_) {
printf(".");
if(!new_adb_level) {
// Transition to low.
constexpr float clock_rate = 894886.25;
@ -212,6 +213,10 @@ uint8_t GLU::get_port_input(int port) {
status_ &= ~uint8_t(CPUFlags::CommandRegisterFull);
break;
}
if(register_address_ == 1) {
printf("[C %02x]", registers_[1]);
}
return registers_[register_address_];
case 1:
// printf("IIe keyboard read\n");

2
Machines/Apple/AppleIIgs/AppleIIgs.cpp
View File

@ -793,7 +793,7 @@ class ConcreteMachine:
// }
if(operation == CPU::WDC65816::BusOperation::ReadOpcode) {
// log = (address >= 0xff6cdc) && (address < 0xff6d43);
log = (address >= 0x00d300) && (address < 0x00d600);
// log = (address >= 0x00d300) && (address < 0x00d600);
}
// log &= !((operation == CPU::WDC65816::BusOperation::ReadOpcode) && ((address < 0xff6a2c) || (address >= 0xff6a9c)));
if(log) {