6502 processor status register
What is a FLAGS register on a 6502 CPU?
The flags register, also called processor status or just P, is one of the six architectural registers on the 6502 family CPU. It is composed of six one-bit registers; instructions modify one or more bits and leave others unchanged. Instructions that save or restore the flags map them to bits in the architectural 'P' register as follows:
How to isolate a byte from a processor status register?
LDA #%00000010 ; Load a bitmask into the Accumulator to isolate bit #1. BIT $0C01 ; Test the byte at address $0C01 against the bitmask. Let us say that the byte value at that address is %10001111. After the BIT instruction the state of the Processor Status register will be as follows: The Negative flag will be set.
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6502.pdf
PROCESSOR. STATUS. REGISTER. P. INSTRUCTION. REGISTER. NOTE: 1. CLOCK GENERATOR IS NOT INCLUDED ON SY651X. 2. ADDRESSING CAPABILITY AND CONTROL OPTIONS VARY |
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W65C02S Microprocessor DATA SHEET
8-bit ALU Accumulator |
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6502 Assembly Language Subroutines
BDIZ C Processor Status Register P. -Carry. -Zero. -Interrupt disable. -Decimal mode. -Break command. Not used (Logic 1). -Overflow. Negative (Sign). |
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W65C02S 8–bit Microprocessor
8 avr. 2022 The 8-bit Processor Status Register (P) contains status flags and mode ... The BRK instruction for both the NMOS 6502 and 65C02 is a 2 byte ... |
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R650X and R651X Microprocessors (CPU)
The R6502 and R6512 can address 64K bytes with a 16-bit address bus (AO-A15); the R6504 R6507 |
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W65C02S 8–bit Microprocessor
8 oct. 2018 The 8-bit Processor Status Register (P) contains status flags and mode ... The BRK instruction for both the NMOS 6502 and 65C02 is a 2 byte ... |
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Programming the 65816
The Full-Featured 65x Processor: The 65816 in Native Mode . 6502/65C02 Addressing Modes on the 65816. ... Push Processor Status Register. |
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65CE02 MICROPROCESSOR
The Commodore 65CE02 is an enhanced version of the popular 8-bit 6502. designed with entirety new processor status register are then stored on the stack. |
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Rockwell
Each CPU in the R65C00/21 is effectively a standard R6502 CPU with 10 extra instructions utilizing Each CPU has its own Processor Status Register (PSRA. |
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6510 MICROPROCESSOR WITH I/O
a common memory. The internal processor architecture is identical to the Commodore Semiconductor Group 6502 to provide software compatibility. FEATURES |
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Rockwell - 6502org
There are two Processor Status Registers, one for each CPU 3-13 Page 12 R65C00/21 • R65C29 Dual CMOS Microcomputer |
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INI MOS - 6502org
program The Program Counter is incremented each time an instruction or data is fetched from memory Processor Status Register The 8-bit Processor Status |
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6502 Stack - JHU Computer Science
Computer Systems Fundamentals: 6502 Stack 20 September 2019 PHP: push processor status to stack – PLP: pull TSX: transfer stack pointer to X register |
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6502 Interrupt and Bus - JHU Computer Science
6502 CPU processes sequence of instructions Interrupt call pushes status register to stack • Detect what BD 04 01 LDA $0104,X ; load stored status register |
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6502pdf - Description
The program counter and processor status register are stored in the stack The microprocessor will then set the inter- rupt mask flag high so that no further IRQs |
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6502 - Description
The Program Counter and Processor Status Register are stored in the stack The microprocessor will then set the interrupt mask flag high so that no futher inter- |
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Vic_revealedpdf - DigitalOcean
6502 Microprocessor 3 - Memory Usage and 6502 Instruction Cycle 7 - Accumulator and Arithmetic 11 – Addressing Modes - Processor Status Register and |
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W65C02S Microprocessor DATA SHEET - Index of
The 8-bit Processor Status Register (P) contains status flags and mode select bits The BRK instruction for both the NMOS 6502 and 65C02 is a 2 byte |
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Advanced 6502 Assembly Language Programming on the Apple //e
INDEX REGISTER 15 PCL PCH PROGRAM COUNTER S 1 STACK POINTER STATUS REGISTER C Carry Z Zero I Interrupt Disable D Decimal Mode |
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20 Interrupts and Breaks
the 6502 On the Apple / /, the NMI is almost never used As this type of of the Program Counter and Status register are pushed on to the hardware stack |
