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Use specific types for enums.

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This commit is contained in:
Zellyn Hunter 2013-02-28 16:33:39 -08:00
parent f1299f6f7f
commit 77c24879e3
3 changed files with 21 additions and 20 deletions
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2
asm/disasm.go
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@ -25,7 +25,7 @@ func bytesString(byte0, byte1, byte2 byte, length int) string {
// addrString returns the address part of a 6502 assembly language // addrString returns the address part of a 6502 assembly language
// instruction. // instruction.
func addrString(pc uint16, byte1, byte2 byte, length int, mode int) string { func addrString(pc uint16, byte1, byte2 byte, length int, mode opcodes.AddressingMode) string {
addr16 := uint16(byte1) + uint16(byte2)<<8 addr16 := uint16(byte1) + uint16(byte2)<<8
addrRel := uint16(int32(pc+2) + int32(int8(byte1))) addrRel := uint16(int32(pc+2) + int32(int8(byte1)))
switch mode { switch mode {

8
cpu/cpu.go
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@ -11,8 +11,10 @@ import (
) )
// Chip versions. // Chip versions.
type CpuVersion int
const ( const (
VERSION_6502 = iota VERSION_6502 CpuVersion = iota
VERSION_65C02 VERSION_65C02
) )
@ -76,11 +78,11 @@ type cpu struct {
t Ticker t Ticker
r registers r registers
oldPC uint16 oldPC uint16
version int version CpuVersion
} }
// Create and return a new Cpu object with the given memory, ticker, and of the given version. // Create and return a new Cpu object with the given memory, ticker, and of the given version.
func NewCPU(memory Memory, ticker Ticker, version int) Cpu { func NewCPU(memory Memory, ticker Ticker, version CpuVersion) Cpu {
c := cpu{m: memory, t: ticker, version: version} c := cpu{m: memory, t: ticker, version: version}
c.r.P |= FLAG_UNUSED // Set unused flag to 1 c.r.P |= FLAG_UNUSED // Set unused flag to 1
return &c return &c

31
opcodes/opcodes.go
View File

@ -6,8 +6,10 @@ function tables.
package opcodes package opcodes
// Opcode addressing modes. // Opcode addressing modes.
type AddressingMode int
const ( const (
MODE_IMPLIED = iota MODE_IMPLIED AddressingMode = iota
MODE_ABSOLUTE MODE_ABSOLUTE
MODE_INDIRECT MODE_INDIRECT
MODE_RELATIVE MODE_RELATIVE
@ -22,16 +24,20 @@ const (
MODE_A MODE_A
) )
// Opcode read/write semantics // Opcode read/write semantics: does the opcode read, write, or
// rmw. Useful to distinguish between instructions further than just
// addressing mode.
type ReadWrite int
const ( const (
MEM_NONE = 0 RW_X ReadWrite = 0 // Don't care
MEM_R = 1 RW_R ReadWrite = 1
MEM_W = 2 RW_W ReadWrite = 2
MEM_RMW = 3 RW_RMW ReadWrite = 3
) )
// Lengths of instructions for each addressing mode. // Lengths of instructions for each addressing mode.
var ModeLengths = map[int]int{ var ModeLengths = map[AddressingMode]int{
MODE_IMPLIED: 1, MODE_IMPLIED: 1,
MODE_ABSOLUTE: 3, MODE_ABSOLUTE: 3,
MODE_INDIRECT: 3, MODE_INDIRECT: 3,
@ -47,18 +53,11 @@ var ModeLengths = map[int]int{
MODE_A: 1, MODE_A: 1,
} }
const (
RW_X = 0 // Don't care
RW_R = 1
RW_W = 2
RW_RMW = 3
)
// Opcode stores information about instructions. // Opcode stores information about instructions.
type Opcode struct { type Opcode struct {
Name string Name string
Mode int Mode AddressingMode
RW int RW ReadWrite
} }
// Fake NoOp instruction used when disassembling. // Fake NoOp instruction used when disassembling.