CPU: Difference between revisions
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The NES CPU core is based on the 6502 processor and runs at approximately 1.79 MHz (1.66 MHz in a PAL NES). It is made by Ricoh and lacks the MOS6502's decimal mode. In the NTSC NES, the RP2A03 chip contains the CPU and APU; in the PAL NES, the CPU and APU are contained within the RP2A07 chip. | The NES CPU core is based on the 6502 processor and runs at approximately 1.79 MHz (1.66 MHz in a PAL NES). It is made by Ricoh and lacks the MOS6502's decimal mode. In the NTSC NES, the RP2A03 chip contains the CPU and APU; in the PAL NES, the CPU and APU are contained within the RP2A07 chip. | ||
<noinclude> | |||
* Instruction list | * Instruction list | ||
* Memory map | * Memory map | ||
* Pinout | * [[CPU_PINOUT_AND_SIGNAL_DESCRIPTION|Pinout]] | ||
* Powerup state | * Powerup state | ||
* status flag behavior | * status flag behavior | ||
</noinclude> | |||
Revision as of 06:41, 11 June 2009
The NES CPU core is based on the 6502 processor and runs at approximately 1.79 MHz (1.66 MHz in a PAL NES). It is made by Ricoh and lacks the MOS6502's decimal mode. In the NTSC NES, the RP2A03 chip contains the CPU and APU; in the PAL NES, the CPU and APU are contained within the RP2A07 chip.
- Instruction list
- Memory map
- Pinout
- Powerup state
- status flag behavior
Note
- The CPU's clock is obtained by dividing a 21.477272 MHz clock source by 12 (26.601712 MHz divided by 16 for PAL).
- Kevtris has confirmed that all illegal 6502 opcodes execute identically on the 2A03/2A07. He has even went as far as to integrate them into the CopyNES BIOS.
