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Adds the shift register interrupt.

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This commit is contained in:
Thomas Harte 2019-05-08 15:02:07 -04:00
parent 8b72043f33
commit 2ba0364850
2 changed files with 18 additions and 2 deletions
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19
Components/6522/Implementation/6522Implementation.hpp
View File

@ -84,7 +84,10 @@ template <typename T> void MOS6522<T>::set_register(int address, uint8_t value)
break;
// Shift
case 0xa: registers_.shift = value; break;
case 0xa:
registers_.shift = value;
shift_bits_remaining_ = 8;
break;
// Control
case 0xb:
@ -175,7 +178,9 @@ template <typename T> uint8_t MOS6522<T>::get_register(int address) {
return registers_.timer[1] & 0x00ff;
case 0x9: return registers_.timer[1] >> 8;
case 0xa: return registers_.shift;
case 0xa:
shift_bits_remaining_ = 8;
return registers_.shift;
case 0xb: return registers_.auxiliary_control;
case 0xc: return registers_.peripheral_control;
@ -363,11 +368,21 @@ template <typename T> void MOS6522<T>::set_control_line_output(Port port, Line l
template <typename T> void MOS6522<T>::shift_in() {
registers_.shift = uint8_t((registers_.shift << 1) | (control_inputs_[1].lines[1] ? 1 : 0));
--shift_bits_remaining_;
if(!shift_bits_remaining_) {
registers_.interrupt_flags |= InterruptFlag::ShiftRegister;
reevaluate_interrupts();
}
}
template <typename T> void MOS6522<T>::shift_out() {
set_control_line_output(Port::B, Line::Two, registers_.shift & 0x80);
registers_.shift <<= 1;
--shift_bits_remaining_;
if(!shift_bits_remaining_) {
registers_.interrupt_flags |= InterruptFlag::ShiftRegister;
reevaluate_interrupts();
}
}
}

1
Components/6522/Implementation/6522Storage.hpp
View File

@ -50,6 +50,7 @@ class MOS6522Storage {
bool timer_is_running_[2] = {false, false};
bool last_posted_interrupt_status_ = false;
int shift_bits_remaining_ = 8;
enum InterruptFlag: uint8_t {
CA2ActiveEdge = 1 << 0,