bsnes/snes/chip/dsp1/dsp1emu.hpp

130 lines
5.3 KiB
C++
Executable File

// DSP-1's emulation code
//
// Based on research by Overload, The Dumper, Neviksti and Andreas Naive
// Date: June 2006
#ifndef __DSP1EMUL_H
#define __DSP1EMUL_H
#define DSP1_VERSION 0x0102
class Dsp1
{
public:
// The DSP-1 status register has 16 bits, but only
// the upper 8 bits can be accessed from an external device, so all these
// positions are referred to the upper byte (bits D8 to D15)
enum SrFlags {DRC=0x04, DRS=0x10, RQM=0x80};
// According to Overload's docs, these are the meanings of the flags:
// DRC: The Data Register Control (DRC) bit specifies the data transfer length to and from the host CPU.
// 0: Data transfer to and from the DSP-1 is 16 bits.
// 1: Data transfer to and from the DSP-1 is 8 bits.
// DRS: The Data Register Status (DRS) bit indicates the data transfer status in the case of transfering 16-bit data.
// 0: Data transfer has terminated.
// 1: Data transfer in progress.
// RQM: The Request for Master (RQM) indicates that the DSP1 is requesting host CPU for data read/write.
// 0: Internal Data Register Transfer.
// 1: External Data Register Transfer.
Dsp1();
uint8 getSr(); // return the status register's high byte
uint8 getDr();
void setDr(uint8 iDr);
void reset();
void serialize(serializer&);
private:
enum FsmMajorState {WAIT_COMMAND, READ_DATA, WRITE_DATA};
enum MaxDataAccesses {MAX_READS=7, MAX_WRITES=1024};
struct Command {
void (Dsp1::*callback)(int16 *, int16 *);
unsigned int reads;
unsigned int writes;
};
static const Command mCommandTable[];
static const int16 MaxAZS_Exp[16];
static const int16 SinTable[];
static const int16 MulTable[];
static const uint16 DataRom[];
struct SharedData { // some RAM variables shared between commands
int16 MatrixA[3][3]; // attitude matrix A
int16 MatrixB[3][3];
int16 MatrixC[3][3];
int16 CentreX, CentreY, CentreZ; // center of projection
int16 CentreZ_C, CentreZ_E;
int16 VOffset; // vertical offset of the screen with regard to the centre of projection
int16 Les, C_Les, E_Les;
int16 SinAas, CosAas;
int16 SinAzs, CosAzs;
int16 SinAZS, CosAZS;
int16 SecAZS_C1, SecAZS_E1;
int16 SecAZS_C2, SecAZS_E2;
int16 Nx, Ny, Nz; // normal vector to the screen (norm 1, points toward the center of projection)
int16 Gx, Gy, Gz; // center of the screen (global coordinates)
int16 Hx, Hy; // horizontal vector of the screen (Hz=0, norm 1, points toward the right of the screen)
int16 Vx, Vy, Vz; // vertical vector of the screen (norm 1, points toward the top of the screen)
} shared;
uint8 mSr; // status register
int mSrLowByteAccess;
uint16 mDr; // "internal" representation of the data register
unsigned mFsmMajorState; // current major state of the FSM
uint8 mCommand; // current command processed by the FSM
uint8 mDataCounter; // #uint16 read/writes counter used by the FSM
int16 mReadBuffer[MAX_READS];
int16 mWriteBuffer[MAX_WRITES];
bool mFreeze; // need explanation? ;)
void fsmStep(bool read, uint8 &data); // FSM logic
// commands
void memoryTest(int16 *input, int16 *output);
void memoryDump(int16 *input, int16 *output);
void memorySize(int16 *input, int16 *output);
void multiply(int16* input, int16* output);
void multiply2(int16* input, int16* output);
void inverse(int16 *input, int16 *output);
void triangle(int16 *input, int16 *output);
void radius(int16 *input, int16 *output);
void range(int16 *input, int16 *output);
void range2(int16 *input, int16 *output);
void distance(int16 *input, int16 *output);
void rotate(int16 *input, int16 *output);
void polar(int16 *input, int16 *output);
void attitudeA(int16 *input, int16 *output);
void attitudeB(int16 *input, int16 *output);
void attitudeC(int16 *input, int16 *output);
void objectiveA(int16 *input, int16 *output);
void objectiveB(int16 *input, int16 *output);
void objectiveC(int16 *input, int16 *output);
void subjectiveA(int16 *input, int16 *output);
void subjectiveB(int16 *input, int16 *output);
void subjectiveC(int16 *input, int16 *output);
void scalarA(int16 *input, int16 *output);
void scalarB(int16 *input, int16 *output);
void scalarC(int16 *input, int16 *output);
void gyrate(int16 *input, int16 *output);
void parameter(int16 *input, int16 *output);
void raster(int16 *input, int16 *output);
void target(int16 *input, int16 *output);
void project(int16 *input, int16 *output);
// auxiliar functions
int16 sin(int16 Angle);
int16 cos(int16 Angle);
void inverse(int16 Coefficient, int16 Exponent, int16 &iCoefficient, int16 &iExponent);
int16 denormalizeAndClip(int16 C, int16 E);
void normalize(int16 m, int16 &Coefficient, int16 &Exponent);
void normalizeDouble(int32 Product, int16 &Coefficient, int16 &Exponent);
int16 shiftR(int16 C, int16 E);
};
#endif