示例#1
0
/**
 * mdp_host_reg_set_all_z80(): Set all Z80 registers.
 * @param reg_struct Pointer to mdp_reg_psg_t struct to get the registers from.
 * @return MDP error code.
 */
static int mdp_host_reg_set_all_z80(void *reg_struct)
{
	mdp_reg_z80_t *reg_z80 = (mdp_reg_z80_t*)reg_struct;
	
	/* Main registers. */
	mdZ80_set_AF(&M_Z80, reg_z80->AF);
	M_Z80.BC.w.BC = reg_z80->BC;
	M_Z80.DE.w.DE = reg_z80->DE;
	M_Z80.HL.w.HL = reg_z80->HL;
	M_Z80.IX.w.IX = reg_z80->IX;
	M_Z80.IY.w.IY = reg_z80->IY;
	
	/* Shadow registers. */
	mdZ80_set_AF2(&M_Z80, reg_z80->AF2);
	M_Z80.BC2.w.BC2 = reg_z80->BC2;
	M_Z80.DE2.w.DE2 = reg_z80->DE2;
	M_Z80.HL2.w.HL2 = reg_z80->HL2;
	
	/* Other registers. */
	mdZ80_set_PC(&M_Z80, reg_z80->PC);
	M_Z80.I = reg_z80->I;
	M_Z80.R.b.R1 = reg_z80->R;
	M_Z80.IM = reg_z80->IM & 3;
	M_Z80.IFF.b.IFF1 = (reg_z80->IFF & 1);
	M_Z80.IFF.b.IFF2 = ((reg_z80->IFF & 2) >> 1);
	
	return MDP_ERR_OK;
}
示例#2
0
/**
 * Reset the Z80 CPU.
 * This is equivalent to asserting the !RESET line.
 * @param z80 Pointer to Z80 context.
 */
void mdZ80_soft_reset(mdZ80_context *z80)
{
	/**
	 * References:
	 * [1] "The Undocumented Z80 Docuemnted" by Sean Young, v0.91 (2005/09/18)
	 * [2] http://gs_server.gerbilsoft.ddns.info/bugs/show_bug.cgi?id=47
	 */
	
	// NOTE: Both [1] and [2] say that other registers are *not* touched
	// when !RESET is asserted, so they're left as-is.
	
	// TODO: Write a test program for MD, then test it on actual hardware.
	
	// Z80 program starts at 0x0000.
	mdZ80_set_PC(z80, 0);	// old Gens; [1]
	
	// TODO: Are IX and IY actually reset on !RESET?
	z80->IX.w = 0xFFFF;	// old Gens; also genplus-gx
	z80->IY.w = 0xFFFF;	// old Gens; also genplus-gx
	
	// TODO: Initialize AF2 to 0xFFFF?
	mdZ80_set_AF(z80, 0xFFFF);	// [1]; Gens originally used 0x4000 (ZF only).
	z80->SP.w = 0xFFFF;		// [1]
	z80->IFF = 0;			// [1]
	z80->R = 0;			// [2]
	z80->I = 0;			// [2]
	z80->IM = 0;			// [1]
}