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Peripherals sync with instantaneous operations of 6502 #23

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DurandA opened this issue Dec 10, 2019 · 1 comment
Open

Peripherals sync with instantaneous operations of 6502 #23

DurandA opened this issue Dec 10, 2019 · 1 comment

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@DurandA
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DurandA commented Dec 10, 2019

This is more a question than a real issue, albeit that could be an issue.

Hasn't the CPU a few cycles of advance to the peripherals of the NES? The olc6502 performs the whole instruction in the first clock of an instruction:

// Perform operation
uint8_t additional_cycle2 = (this->*lookup[opcode].operate)();

// Decrement the number of cycles remaining for this instruction
cycles--;

@OneLoneCoder mentioned this emulator emulates only the behaviour and is not cycle-accurate but doesn't this cause sync issues? In particular, I am thinking of the PPU since it performs operations at every clock cycle.

@DurandA
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DurandA commented Dec 10, 2019

This is related to #9.

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