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Gave the 6522 a full and grouped register set.
This commit is contained in:
Thomas Harte
parent
12d1cac751
commit
a71259dec3
@ -38,66 +38,106 @@ template <class T> class MOS6522 {
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}
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MOS6522() :
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_data_direction{0, 0},
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_timer_is_running{false, false}
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{}
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void set_register(int address, uint8_t value)
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{
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printf("6522: %d <- %02x\n", address, value);
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address &= 0xf;
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switch(address)
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{
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case 0x00:
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_registers.output[1] = value;
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break;
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case 0x01:
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_registers.output[0] = value;
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break;
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case 0xf:
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_registers.output[0] = value;
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break;
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case 0x02:
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_registers.data_direction[1] = value;
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break;
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case 0x03:
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_registers.data_direction[0] = value;
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break;
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// Timer 1
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case 0x06: case 0x04: _interval_timer_latch[0] = (_interval_timer_latch[0]&0xff00) | value; break;
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case 0x06: case 0x04: _registers.timer_latch[0] = (_registers.timer_latch[0]&0xff00) | value; break;
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case 0x05: case 0x07:
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_interval_timer_latch[0] = (_interval_timer_latch[0]&0x00ff) | (uint16_t)(value << 8);
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_interrupt_flags &= ~InterruptFlag::Timer1;
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_registers.timer_latch[0] = (_registers.timer_latch[0]&0x00ff) | (uint16_t)(value << 8);
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_registers.interrupt_flags &= ~InterruptFlag::Timer1;
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if(address == 0x05)
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{
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_interval_timer[0] = _interval_timer_latch[0];
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_registers.timer[0] = _registers.timer_latch[0];
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_timer_is_running[0] = true;
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}
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reevaluate_interrupts();
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break;
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// Timer 2
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case 0x08: _interval_timer_latch[1] = value; break;
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case 0x08: _registers.timer_latch[1] = value; break;
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case 0x09:
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_interrupt_flags &= ~InterruptFlag::Timer2;
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_interval_timer[1] = _interval_timer_latch[1] | (uint16_t)(value << 8);
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_registers.interrupt_flags &= ~InterruptFlag::Timer2;
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_registers.timer[1] = _registers.timer_latch[1] | (uint16_t)(value << 8);
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_timer_is_running[1] = true;
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reevaluate_interrupts();
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break;
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case 11: _auxiliary_control_register = value; break;
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case 13:
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if(!(value&0x80)) value = ~value;
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_interrupt_mask = value;
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// Shift
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case 0xa: _registers.shift = value; break;
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// Control
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case 0xb: _registers.auxiliary_control = value; break;
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case 0xc: _registers.peripheral_control = value; break;
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// Interrupt control
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case 0xd:
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_registers.interrupt_flags = value; // TODO: really?
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reevaluate_interrupts();
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break;
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case 14:
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case 0xe:
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if(!(value&0x80)) value = ~value;
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_registers.interrupt_enable = value;
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reevaluate_interrupts();
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break;
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}
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}
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uint8_t get_register(int address)
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{
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printf("6522: %d\n", address);
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address &= 0xf;
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switch(address)
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{
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case 0x00: return _registers.input[1];
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case 0x01: return _registers.input[0];
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case 0x02: return _registers.data_direction[1];
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case 0x03: return _registers.data_direction[0];
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case 0x0f: return _registers.input[1];
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// Timer 1
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case 0x04:
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_interrupt_flags &= ~InterruptFlag::Timer1;
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_registers.interrupt_flags &= ~InterruptFlag::Timer1;
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reevaluate_interrupts();
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return _interval_timer[0] & 0x00ff;
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case 0x05: return _interval_timer[0] >> 8;
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case 0x06: return _interval_timer_latch[0] & 0x00ff;
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case 0x07: return _interval_timer_latch[0] >> 8;
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return _registers.timer[0] & 0x00ff;
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case 0x05: return _registers.timer[0] >> 8;
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case 0x06: return _registers.timer_latch[0] & 0x00ff;
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case 0x07: return _registers.timer_latch[0] >> 8;
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case 11: return _auxiliary_control_register;
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case 13: return _interrupt_flags;
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case 14: return _interrupt_mask;
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// Timer 2
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case 0x08:
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_registers.interrupt_flags &= ~InterruptFlag::Timer2;
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reevaluate_interrupts();
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return _registers.timer[1] & 0x00ff;
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case 0x09: return _registers.timer[1] >> 8;
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case 0x0a: return _registers.shift;
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case 0x0b: return _registers.auxiliary_control;
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case 0x0c: return _registers.peripheral_control;
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case 0x0d: return _registers.interrupt_flags;
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case 0x0e: return _registers.interrupt_enable;
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}
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return 0xff;
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@ -105,25 +145,25 @@ template <class T> class MOS6522 {
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void run_for_cycles(unsigned int number_of_cycles)
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{
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_interval_timer[0] -= number_of_cycles;
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_interval_timer[1] -= number_of_cycles;
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_registers.timer[0] -= number_of_cycles;
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_registers.timer[1] -= number_of_cycles;
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if(!_interval_timer[1] && _timer_is_running[1])
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if(!_registers.timer[1] && _timer_is_running[1])
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{
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_timer_is_running[1] = false;
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_interrupt_flags |= InterruptFlag::Timer2;
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_registers.interrupt_flags |= InterruptFlag::Timer2;
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reevaluate_interrupts();
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}
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if(!_interval_timer[0] && _timer_is_running[0])
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if(!_registers.timer[0] && _timer_is_running[0])
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{
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_interrupt_flags |= InterruptFlag::Timer1;
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_registers.interrupt_flags |= InterruptFlag::Timer1;
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reevaluate_interrupts();
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// TODO: reload shouldn't occur for a further 1.5 cycles
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if(_auxiliary_control_register&0x40)
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if(_registers.auxiliary_control&0x40)
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{
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_interval_timer[0] = _interval_timer_latch[0];
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_registers.timer[0] = _registers.timer_latch[0];
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}
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else
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_timer_is_running[0] = false;
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@ -133,7 +173,7 @@ template <class T> class MOS6522 {
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bool get_interrupt_line()
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{
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uint8_t interrupt_status = _interrupt_flags & (~_interrupt_mask) & 0x7f;
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uint8_t interrupt_status = _registers.interrupt_flags & (~_registers.interrupt_enable) & 0x7f;
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return !!interrupt_status;
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}
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@ -144,16 +184,18 @@ template <class T> class MOS6522 {
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}
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MOS6522Delegate *_delegate;
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uint16_t _interval_timer[2], _interval_timer_latch[2];
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uint8_t _shift_register;
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uint8_t _input_latch[2];
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uint8_t _data_direction[2];
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uint8_t _interrupt_flags, _interrupt_mask;
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struct Registers {
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uint8_t output[2], input[2], data_direction[2];
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uint16_t timer[2], timer_latch[2];
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uint8_t shift;
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uint8_t auxiliary_control, peripheral_control;
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uint8_t interrupt_flags, interrupt_enable;
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Registers() : data_direction{0, 0} {}
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} _registers;
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bool _timer_is_running[2];
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uint8_t _interrupt_flag_register, _interrupt_enable_register;
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uint8_t _peripheral_control_register, _auxiliary_control_register;
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};
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}
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