// LRI $D, #I
// 0000 0000 100d dddd
// iiii iiii iiii iiii
// Load immediate value I to register $D.
//
// DSPSpy discovery: This, and possibly other instructions that load a
// register, has a different behaviour in S40 mode if loaded to AC0.M: The
// value gets sign extended to the whole accumulator! This does not happen in
// S16 mode.
void lri(const UDSPInstruction opc)
{
u8 reg = opc & DSP_REG_MASK;
u16 imm = dsp_fetch_code();
dsp_op_write_reg(reg, imm);
dsp_conditional_extend_accum(reg);
}
void Step()
{
DSPCore_CheckExceptions();
g_dsp.step_counter++;
#if PROFILE
g_dsp.err_pc = g_dsp.pc;
ProfilerAddDelta(g_dsp.err_pc, 1);
if (g_dsp.step_counter == 1)
{
ProfilerInit();
}
if ((g_dsp.step_counter & 0xFFFFF) == 0)
{
ProfilerDump(g_dsp.step_counter);
}
#endif
u16 opc = dsp_fetch_code();
ExecuteInstruction(UDSPInstruction(opc));
if (DSPAnalyzer::code_flags[g_dsp.pc - 1] & DSPAnalyzer::CODE_LOOP_END)
HandleLoop();
}
// LR $D, @M
// 0000 0000 110d dddd
// mmmm mmmm mmmm mmmm
// Move value from data memory pointed by address M to register $D.
void lr(const UDSPInstruction opc)
{
u8 reg = opc & DSP_REG_MASK;
u16 addr = dsp_fetch_code();
u16 val = dsp_dmem_read(addr);
dsp_op_write_reg(reg, val);
dsp_conditional_extend_accum(reg);
}
// Generic jmp implementation
// Jcc addressA
// 0000 0010 1001 cccc
// aaaa aaaa aaaa aaaa
// Jump to addressA if condition cc has been met. Set program counter to
// address represented by value that follows this "jmp" instruction.
void jcc(const UDSPInstruction opc)
{
u16 dest = dsp_fetch_code();
if (CheckCondition(opc & 0xf))
{
g_dsp.pc = dest;
}
}
// SR @M, $S
// 0000 0000 111s ssss
// mmmm mmmm mmmm mmmm
// Store value from register $S to a memory pointed by address M.
void sr(const UDSPInstruction opc)
{
u8 reg = opc & DSP_REG_MASK;
u16 addr = dsp_fetch_code();
if (reg >= DSP_REG_ACM0)
dsp_dmem_write(addr, dsp_op_read_reg_and_saturate(reg - DSP_REG_ACM0));
else
dsp_dmem_write(addr, dsp_op_read_reg(reg));
}
// SI @M, #I
// 0001 0110 mmmm mmmm
// iiii iiii iiii iiii
// Store 16-bit immediate value I to a memory location pointed by address
// M (M is 8-bit value sign extended).
void si(const UDSPInstruction opc)
{
u16 addr = (s8)opc;
u16 imm = dsp_fetch_code();
dsp_dmem_write(addr, imm);
}
