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How many instructions does the 6502 have?
56 instructions
Of the 256 possible opcodes available using an 8-bit pattern, the original 6502 uses 151 of them, organized into 56 instructions with (possibly) multiple addressing modes. Depending on the instruction and addressing mode, the opcode may require zero, one or two additional bytes for operands.
What are the two types of interrupts supported by the 6502 microprocessor?
There are two separate interrupts: maskable and non-maskable. The 6502 will sample these one cycle before the end of each instruction. If the NMI line has become active (it’s edge triggered) then it will perform the NMI routine after this operation completes.
Is 6502 a RISC?
The 6502/65816 processors employ zero page precisely as a RISC processor makes use of its internal registers.
How many transistors are in a MOS 6502?
There are 3218 transistors and 1019 resistors that comprise the “functional” part of the 6502.
Is the 6502 pipelined?
Post subject: Re: Was the original 6502 pipelined? The 6502 was pipelined and the Z80 as well. Pipelining used to refer to the fact that instruction were performed piecemeal in a number of stages requiring multiple clock cycles as opposed to performing the entire instruction in one very long clock cycle.
What used the Z80?
Although used in that role, the Z80 also became one of the most widely used CPUs in desktop computers and home computers from the 1970s to the mid-1980s….Zilog Z80.
| General information | |
|---|---|
| Transistors | 8500 (4μm process) |
| Package(s) | 40-pin DIP |
| Socket(s) | DIP40 |
What is the syntax of the c74-6502 microcode?
The syntax of the C74-6502 microcode is designed to be mnemonic. That is, it is descriptive of function rather than detailing the values of control signals. The microcode is then “assembled” into a binary representation of microinstructions stored in Control ROMs on the CPU.
How does the fetchopcode work on the c74-6502?
The C74-6502’s datapath allows values to be loaded from memory while the ALU is in use, so the FetchOpcode can complete during the ALU cycle itself. In summary then, the LDA Immediate instruction is made up of two microinstructions, each of which executes in one cycle.
Which is the best site to find out about the 6502?
Visual6502 is the best site to find out about the inner workings of the 6502. I’ll be using the “Random Control Logic” signal names as used in the simulator, which are the same names used in Hanson’s block diagram.
What is the two stage pipeline in the 6502?
The 6502 has a kind of two-stage pipeline, where the next instruction is already fetched and decoded while the last stage (s) of the previous instruction still executes. In T0, the next opcoded is prepared to be fetched, and in T1, the opcode is decoded, and the next byte after the opcode is prepared to be fetched.