Exemplo n.º 1
0
// 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);
}
Exemplo n.º 2
0
// 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);
}