Steve2/src/cpu/instructions/6502_instr_shift_rotate.h

133 lines
3.4 KiB
C

//
// main.c
// 6502
//
// Created by Tamas Rudnai on 7/14/19.
// Copyright © 2019 GameAlloy. All rights reserved.
//
#ifndef __6502_INSTR_SHIFT_ROTATE_H__
#define __6502_INSTR_SHIFT_ROTATE_H__
/**
ASL Shift Left One Bit (Memory or Accumulator)
C <- [76543210] <- 0 N Z C I D V
+ + + - - -
addressing assembler opc bytes cyles
--------------------------------------------
accumulator ASL A 0A 1 2
zeropage ASL oper 06 2 5
zeropage,X ASL oper,X 16 2 6
absolute ASL oper 0E 3 6
absolute,X ASL oper,X 1E 3 7
**/
INLINE void ASL( uint8_t * dst ) {
dbgPrintf("ASL ");
disPrintf(disassembly.inst, "ASL");
m6502.C = *dst >> 7;
set_flags_NZ( *dst <<= 1 );
}
INLINE void ASLA() {
dbgPrintf("ASL ");
disPrintf(disassembly.inst, "ASL");
m6502.C = m6502.A >> 7;
set_flags_NZ( m6502.A <<= 1 );
}
/**
LSR Shift One Bit Right (Memory or Accumulator)
0 -> [76543210] -> C N Z C I D V
0 + + - - -
addressing assembler opc bytes cyles
--------------------------------------------
accumulator LSR A 4A 1 2
zeropage LSR oper 46 2 5
zeropage,X LSR oper,X 56 2 6
absolute LSR oper 4E 3 6
absolute,X LSR oper,X 5E 3 7
**/
INLINE void LSR( uint8_t * dst ) {
dbgPrintf("LSR ");
disPrintf(disassembly.inst, "LSR");
m6502.C = *dst & 1;
set_flags_NZ( *dst >>= 1 );
}
INLINE void LSRA() {
dbgPrintf("LSR ");
disPrintf(disassembly.inst, "LSR");
m6502.C = m6502.A & 1;
set_flags_NZ( m6502.A >>= 1 );
}
/**
ROL Rotate One Bit Left (Memory or Accumulator)
C <- [76543210] <- C N Z C I D V
+ + + - - -
addressing assembler opc bytes cyles
--------------------------------------------
accumulator ROL A 2A 1 2
zeropage ROL oper 26 2 5
zeropage,X ROL oper,X 36 2 6
absolute ROL oper 2E 3 6
absolute,X ROL oper,X 3E 3 7
**/
INLINE void ROL( uint8_t * dst ) {
dbgPrintf("ROL ");
disPrintf(disassembly.inst, "ROL");
uint8_t C = m6502.C;
m6502.C = *dst >> 7;
*dst <<= 1;
set_flags_NZ( *dst |= C );
}
INLINE void ROLA() {
dbgPrintf("ROL ");
disPrintf(disassembly.inst, "ROL");
uint8_t C = m6502.C;
m6502.C = m6502.A >> 7;
m6502.A <<= 1;
set_flags_NZ( m6502.A |= C );
}
/**
ROR Rotate One Bit Right (Memory or Accumulator)
C -> [76543210] -> C N Z C I D V
+ + + - - -
addressing assembler opc bytes cyles
--------------------------------------------
accumulator ROR A 6A 1 2
zeropage ROR oper 66 2 5
zeropage,X ROR oper,X 76 2 6
absolute ROR oper 6E 3 6
absolute,X ROR oper,X 7E 3 7
**/
INLINE void ROR( uint8_t * dst ) {
dbgPrintf("ROR ");
disPrintf(disassembly.inst, "ROR");
uint8_t C = m6502.C << 7;
m6502.C = *dst & 1;
*dst >>= 1;
set_flags_NZ( *dst |= C );
}
INLINE void RORA() {
dbgPrintf("ROR ");
disPrintf(disassembly.inst, "ROR");
uint8_t C = m6502.C << 7;
m6502.C = m6502.A & 1;
m6502.A >>= 1;
set_flags_NZ( m6502.A |= C );
}
#endif // __6502_INSTR_SHIFT_ROTATE_H__