void C6821::set_input_cb2(int data)
{
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* CB2 is in input mode */
if((ControlB & CTRL_C2_OUTPUT) == 0)
{
/* the new state has caused a transition */
if (InputCB2 ^ data)
{
/* handle the active transition */
if ((data && (ControlB & 2)) || (!data && (ControlB & 2) == 0))
{
/* mark the IRQ */
IRQB2 = 1;
/* update externals */
update_6821_interrupts();
}
}
}
/* set the new value for CA2 */
InputCB2 = data;
// p->in_set |= PIA_IN_SET_CB2;
}
void pia_set_input_cb2(int which, int data)
{
struct pia6821 *p = pia + which;
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* CB2 is in input mode */
if (C2_INPUT(p->ctl_b))
{
/* the new state has caused a transition */
if (p->in_cb2 ^ data)
{
/* handle the active transition */
if ((data && C2_LOW_TO_HIGH(p->ctl_b)) || (!data && C2_HIGH_TO_LOW(p->ctl_b)))
{
/* mark the IRQ */
p->irq_b2 = 1;
/* update externals */
update_6821_interrupts(p);
}
}
}
/* set the new value for CA2 */
p->in_cb2 = data;
p->in_set |= PIA_IN_SET_CB2;
}
void pia_set_input_cb1(int which, int data)
{
pia6821 *p = pia + which;
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* the new state has caused a transition */
if (p->in_cb1 ^ data)
{
/* handle the active transition */
if ((data && C1_LOW_TO_HIGH(p->ctl_b)) || (!data && C1_HIGH_TO_LOW(p->ctl_b)))
{
/* mark the IRQ */
p->irq_b1 = 1;
/* update externals */
update_6821_interrupts(p);
/* If CB2 is configured as a write-strobe output which is reset by a CB1
transition, this reset will only happen when a read from port B implicitly
clears the IRQ B1 flag. So we handle the CB2 reset there. Note that this
is different from what happens with port A. */
}
}
/* set the new value for CB1 */
p->in_cb1 = data;
p->in_set |= PIA_IN_SET_CB1;
}
void C6821::set_input_cb1(int data)
{
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* the new state has caused a transition */
if (InputCB1 ^ data)
{
/* handle the active transition */
if ((data && (ControlB & 2)) || (!data && (ControlB & 2) == 0))
{
/* mark the IRQ */
IRQB1 = 1;
/* update externals */
update_6821_interrupts();
/* If CB2 is configured as a write-strobe output which is reset by a CB1
transition, this reset will only happen when a read from port B implicitly
clears the IRQ B1 flag. So we handle the CB2 reset there. Note that this
is different from what happens with port A. */
}
}
/* set the new value for CB1 */
InputCB1 = data;
// p->in_set |= PIA_IN_SET_CB1;
}
static void pia_postload(int which)
{
struct pia6821 *p = pia + which;
update_6821_interrupts(p);
if (p->intf->out_a_func && p->ddr_a) p->intf->out_a_func(0, p->out_a & p->ddr_a);
if (p->intf->out_b_func && p->ddr_b) p->intf->out_b_func(0, p->out_b & p->ddr_b);
if (p->intf->out_ca2_func) p->intf->out_ca2_func(0, p->out_ca2);
if (p->intf->out_cb2_func) p->intf->out_cb2_func(0, p->out_cb2);
}
void pia_set_input_cb1(int which, int data)
{
struct pia6821 *p = pia + which;
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* the new state has caused a transition */
if (p->in_cb1 ^ data)
{
/* handle the active transition */
if ((data && C1_LOW_TO_HIGH(p->ctl_b)) || (!data && C1_HIGH_TO_LOW(p->ctl_b)))
{
/* mark the IRQ */
p->irq_b1 = 1;
/* update externals */
update_6821_interrupts(p);
/* CB2 is configured as output and in write strobe mode and cleared by a CA1 transition */
if (C2_OUTPUT(p->ctl_b) && C2_STROBE_MODE(p->ctl_b) && STROBE_C1_RESET(p->ctl_b))
{
/* the IRQ1 flag must have also been cleared */
if (!p->irq_b1)
{
/* call the CB2 output function */
if (!p->out_cb2)
if (p->intf->out_cb2_func) p->intf->out_cb2_func(0, 1);
/* clear CB2 */
p->out_cb2 = 1;
}
}
}
}
/* set the new value for CB1 */
p->in_cb1 = data;
p->in_set |= PIA_IN_SET_CB1;
}
void pia_set_input_ca1(int which, int data)
{
pia6821 *p = pia + which;
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* the new state has caused a transition */
if (p->in_ca1 ^ data)
{
/* handle the active transition */
if ((data && C1_LOW_TO_HIGH(p->ctl_a)) || (!data && C1_HIGH_TO_LOW(p->ctl_a)))
{
/* mark the IRQ */
p->irq_a1 = 1;
/* update externals */
update_6821_interrupts(p);
/* CA2 is configured as output and in read strobe mode and cleared by a CA1 transition */
if (C2_OUTPUT(p->ctl_a) && C2_STROBE_MODE(p->ctl_a) && STROBE_C1_RESET(p->ctl_a))
{
/* call the CA2 output function */
if (!p->out_ca2)
if (p->intf->out_ca2_func) p->intf->out_ca2_func(0, 1);
/* clear CA2 */
p->out_ca2 = 1;
}
}
}
/* set the new value for CA1 */
p->in_ca1 = data;
p->in_set |= PIA_IN_SET_CA1;
}
void C6821::set_input_ca1(int data)
{
/* limit the data to 0 or 1 */
data = data ? 1 : 0;
/* the new state has caused a transition */
if(InputCA1 ^ data)
{
/* handle the active transition */
if ((data && (ControlA & 2)) || (!data && (ControlA & 2) == 0))
{
/* mark the IRQ */
IRQA1 = 1;
/* update externals */
update_6821_interrupts();
/* CA2 is configured as output and in read strobe mode and cleared by a CA1 transition */
if(ControlA & CTRL_C2_OUTPUT &&
(ControlA & CTRL_C2_SETMODE) == 0 &&
(ControlA & CTRL_STROBE_E_RESET) == 0)
{
/* call the CA2 output function */
if (OutputCA2 == 0 && OutputCA2Func) OutputCA2Func(user,1);
/* clear CA2 */
OutputCA2 = 1;
}
}
}
/* set the new value for CA1 */
InputCA1 = data;
// p->in_set |= PIA_IN_SET_CA1;
}
void pia_write(int which, int offset, int data)
{
struct pia6821 *p = pia + which;
/* adjust offset for 16-bit and ordering */
offset &= 3;
if (p->addr & PIA_ALTERNATE_ORDERING) offset = swizzle_address[offset];
switch (offset)
{
/******************* port A output/DDR write *******************/
case PIA_DDRA:
/* write output register */
if (OUTPUT_SELECTED(p->ctl_a))
{
LOG(("%04x: PIA%d port A write = %02X\n", activecpu_get_previouspc(), which, data));
/* update the output value */
p->out_a = data;/* & p->ddr_a; */ /* NS990130 - don't mask now, DDR could change later */
/* send it to the output function */
if (p->intf->out_a_func && p->ddr_a) p->intf->out_a_func(0, p->out_a & p->ddr_a); /* NS990130 */
}
/* write DDR register */
else
{
LOG(("%04x: PIA%d DDR A write = %02X\n", activecpu_get_previouspc(), which, data));
if (p->ddr_a != data)
{
/* NS990130 - if DDR changed, call the callback again */
p->ddr_a = data;
/* send it to the output function */
if (p->intf->out_a_func && p->ddr_a) p->intf->out_a_func(0, p->out_a & p->ddr_a);
}
}
break;
/******************* port B output/DDR write *******************/
case PIA_DDRB:
/* write output register */
if (OUTPUT_SELECTED(p->ctl_b))
{
LOG(("%04x: PIA%d port B write = %02X\n", activecpu_get_previouspc(), which, data));
/* update the output value */
p->out_b = data;/* & p->ddr_b */ /* NS990130 - don't mask now, DDR could change later */
/* send it to the output function */
if (p->intf->out_b_func && p->ddr_b) p->intf->out_b_func(0, p->out_b & p->ddr_b); /* NS990130 */
/* CB2 is configured as output and in write strobe mode */
if (C2_OUTPUT(p->ctl_b) && C2_STROBE_MODE(p->ctl_b))
{
/* this will cause a transition low; call the output function if we're currently high */
if (p->out_cb2)
if (p->intf->out_cb2_func) p->intf->out_cb2_func(0, 0);
p->out_cb2 = 0;
/* if the CB2 strobe is cleared by the E, reset it right away */
if (STROBE_E_RESET(p->ctl_b))
{
if (p->intf->out_cb2_func) p->intf->out_cb2_func(0, 1);
p->out_cb2 = 1;
}
}
}
/* write DDR register */
else
{
LOG(("%04x: PIA%d DDR B write = %02X\n", activecpu_get_previouspc(), which, data));
if (p->ddr_b != data)
{
/* NS990130 - if DDR changed, call the callback again */
p->ddr_b = data;
/* send it to the output function */
if (p->intf->out_b_func && p->ddr_b) p->intf->out_b_func(0, p->out_b & p->ddr_b);
}
}
break;
/******************* port A control write *******************/
case PIA_CTLA:
/* Bit 7 and 6 read only - PD 16/01/00 */
data &= 0x3f;
LOG(("%04x: PIA%d control A write = %02X\n", activecpu_get_previouspc(), which, data));
/* CA2 is configured as output and in set/reset mode */
/* 10/22/98 - MAB/FMP - any C2_OUTPUT should affect CA2 */
// if (C2_OUTPUT(data) && C2_SET_MODE(data))
if (C2_OUTPUT(data))
{
/* determine the new value */
int temp = SET_C2(data) ? 1 : 0;
/* if this creates a transition, call the CA2 output function */
if (p->out_ca2 ^ temp)
if (p->intf->out_ca2_func) p->intf->out_ca2_func(0, temp);
/* set the new value */
p->out_ca2 = temp;
}
/* update the control register */
p->ctl_a = data;
/* update externals */
update_6821_interrupts(p);
break;
/******************* port B control write *******************/
case PIA_CTLB:
/* Bit 7 and 6 read only - PD 16/01/00 */
data &= 0x3f;
LOG(("%04x: PIA%d control B write = %02X\n", activecpu_get_previouspc(), which, data));
/* CB2 is configured as output and in set/reset mode */
/* 10/22/98 - MAB/FMP - any C2_OUTPUT should affect CB2 */
// if (C2_OUTPUT(data) && C2_SET_MODE(data))
if (C2_OUTPUT(data))
{
/* determine the new value */
int temp = SET_C2(data) ? 1 : 0;
/* if this creates a transition, call the CA2 output function */
if (p->out_cb2 ^ temp)
if (p->intf->out_cb2_func) p->intf->out_cb2_func(0, temp);
/* set the new value */
p->out_cb2 = temp;
}
/* update the control register */
p->ctl_b = data;
/* update externals */
update_6821_interrupts(p);
break;
}
}
int pia_read(int which, int offset)
{
struct pia6821 *p = pia + which;
int val = 0;
/* adjust offset for 16-bit and ordering */
offset &= 3;
if (p->addr & PIA_ALTERNATE_ORDERING) offset = swizzle_address[offset];
switch (offset)
{
/******************* port A output/DDR read *******************/
case PIA_DDRA:
/* read output register */
if (OUTPUT_SELECTED(p->ctl_a))
{
/* update the input */
if ((FPTR)(p->intf->in_a_func) > 0x100)
p->in_a = p->intf->in_a_func(0);
#ifdef MAME_DEBUG
else if ((p->ddr_a ^ 0xff) && !(p->in_set & PIA_IN_SET_A)) {
logerror("PIA%d: Warning! no port A read handler. Assuming pins %02x not connected\n",
which, p->ddr_a ^ 0xff);
p->in_set |= PIA_IN_SET_A; // disable logging
}
#endif // MAME_DEBUG
/* combine input and output values */
val = (p->out_a & p->ddr_a) + (p->in_a & ~p->ddr_a);
/* IRQ flags implicitly cleared by a read */
p->irq_a1 = p->irq_a2 = 0;
update_6821_interrupts(p);
/* CA2 is configured as output and in read strobe mode */
if (C2_OUTPUT(p->ctl_a) && C2_STROBE_MODE(p->ctl_a))
{
/* this will cause a transition low; call the output function if we're currently high */
if (p->out_ca2)
if (p->intf->out_ca2_func) p->intf->out_ca2_func(0, 0);
p->out_ca2 = 0;
/* if the CA2 strobe is cleared by the E, reset it right away */
if (STROBE_E_RESET(p->ctl_a))
{
if (p->intf->out_ca2_func) p->intf->out_ca2_func(0, 1);
p->out_ca2 = 1;
}
}
LOG(("%04x: PIA%d read port A = %02X\n", activecpu_get_previouspc(), which, val));
}
/* read DDR register */
else
{
val = p->ddr_a;
LOG(("%04x: PIA%d read DDR A = %02X\n", activecpu_get_previouspc(), which, val));
}
break;
/******************* port B output/DDR read *******************/
case PIA_DDRB:
/* read output register */
if (OUTPUT_SELECTED(p->ctl_b))
{
/* update the input */
if ((FPTR)(p->intf->in_b_func) > 0x100)
p->in_b = p->intf->in_b_func(0);
#ifdef MAME_DEBUG
else if ((p->ddr_b ^ 0xff) && !(p->in_set & PIA_IN_SET_B)) {
logerror("PIA%d: Error! no port B read handler. Three-state pins %02x are undefined\n",
which, p->ddr_b ^ 0xff);
p->in_set |= PIA_IN_SET_B; // disable logging
}
#endif // MAME_DEBUG
/* combine input and output values */
val = (p->out_b & p->ddr_b) + (p->in_b & ~p->ddr_b);
/* IRQ flags implicitly cleared by a read */
p->irq_b1 = p->irq_b2 = 0;
update_6821_interrupts(p);
LOG(("%04x: PIA%d read port B = %02X\n", activecpu_get_previouspc(), which, val));
}
/* read DDR register */
else
{
val = p->ddr_b;
LOG(("%04x: PIA%d read DDR B = %02X\n", activecpu_get_previouspc(), which, val));
}
break;
/******************* port A control read *******************/
case PIA_CTLA:
/* Update CA1 & CA2 if callback exists, these in turn may update IRQ's */
if ((FPTR)(p->intf->in_ca1_func) > 0x100)
pia_set_input_ca1(which, p->intf->in_ca1_func(0));
#ifdef MAME_DEBUG
else if (!(p->in_set & PIA_IN_SET_CA1)) {
logerror("PIA%d: Warning! no CA1 read handler. Assuming pin not connected\n",which);
p->in_set |= PIA_IN_SET_CA1; // disable logging
}
#endif // MAME_DEBUG
if ((FPTR)(p->intf->in_ca2_func) > 0x100)
pia_set_input_ca2(which, p->intf->in_ca2_func(0));
#ifdef MAME_DEBUG
else if (C2_INPUT(p->ctl_a) && !(p->in_set & PIA_IN_SET_CA2)) {
logerror("PIA%d: Warning! no CA2 read handler. Assuming pin not connected\n",which);
p->in_set |= PIA_IN_SET_CA2; // disable logging
}
#endif // MAME_DEBUG
/* read control register */
val = p->ctl_a;
/* set the IRQ flags if we have pending IRQs */
if (p->irq_a1) val |= PIA_IRQ1;
if (p->irq_a2 && C2_INPUT(p->ctl_a)) val |= PIA_IRQ2;
LOG(("%04x: PIA%d read control A = %02X\n", activecpu_get_previouspc(), which, val));
break;
/******************* port B control read *******************/
case PIA_CTLB:
/* Update CB1 & CB2 if callback exists, these in turn may update IRQ's */
if ((FPTR)(p->intf->in_cb1_func) > 0x100)
pia_set_input_cb1(which, p->intf->in_cb1_func(0));
#ifdef MAME_DEBUG
else if (!(p->in_set & PIA_IN_SET_CB1)) {
logerror("PIA%d: Error! no CB1 read handler. Three-state pin is undefined\n",which);
p->in_set |= PIA_IN_SET_CB1; // disable logging
}
#endif // MAME_DEBUG
if ((FPTR)(p->intf->in_cb2_func) > 0x100)
pia_set_input_cb2(which, p->intf->in_cb2_func(0));
#ifdef MAME_DEBUG
else if (C2_INPUT(p->ctl_b) && !(p->in_set & PIA_IN_SET_CB2)) {
logerror("PIA%d: Error! no CB2 read handler. Three-state pin is undefined\n",which);
p->in_set |= PIA_IN_SET_CB2; // disable logging
}
#endif // MAME_DEBUG
/* read control register */
val = p->ctl_b;
/* set the IRQ flags if we have pending IRQs */
if (p->irq_b1) val |= PIA_IRQ1;
if (p->irq_b2 && C2_INPUT(p->ctl_b)) val |= PIA_IRQ2;
LOG(("%04x: PIA%d read control B = %02X\n", activecpu_get_previouspc(), which, val));
break;
}
return val;
}
void C6821::Write(int reg,u8 data)
{
switch(reg)
{
case c6821_ddra:
if(ControlA & CTRL_OUTPUT)
{
OutputA = data;
if(OutputAFunc && DataA)
OutputAFunc(user,OutputA & DataA);
}
else
{
if(DataA != data)
{
DataA = data;
if(OutputAFunc && DataA)
OutputAFunc(user,OutputA & DataA);
}
}
break;
case c6821_ctrla:
data &= 0x3F;
if(data & CTRL_C2_OUTPUT)
{
u8 t;
if(data & CTRL_C2_SETMODE)
{
if((data & 8) == 0)
t = 0;
else
t = 1;
}
else
t = 1;
if((ControlA & CTRL_C2_OUTPUT) == 0 ||
((ControlA & CTRL_C2_OUTPUT) && (OutputCA2 ^ t)))
{
if(OutputCA2Func)
OutputCA2Func(user,t);
}
OutputCA2 = t;
}
ControlA = data;
update_6821_interrupts();
break;
case c6821_ddrb:
if(ControlB & CTRL_OUTPUT)
{
OutputB = data;
if(OutputBFunc && DataB)
OutputBFunc(user,OutputB & DataB);
if(ControlB & CTRL_C2_OUTPUT && (ControlB & CTRL_C2_SETMODE) == 0)
{
if(OutputCB2 && OutputCB2Func)
OutputCB2Func(user,0);
OutputCB2 = 0;
if(ControlB & CTRL_STROBE_E_RESET)
{
if(OutputCB2Func)
OutputCB2Func(user,1);
OutputCB2 = 1;
}
}
}
else
{
if(DataB != data)
{
DataB = data;
if(OutputBFunc && DataB)
OutputBFunc(user,OutputB & DataB);
}
}
break;
case c6821_ctrlb:
data &= 0x3F;
if(data & CTRL_C2_OUTPUT)
{
u8 t;
if(data & CTRL_C2_SETMODE)
{
if((data & 8) == 0)
t = 0;
else
t = 1;
}
else
t = 1;
if((ControlB & CTRL_C2_OUTPUT) == 0 ||
((ControlB & CTRL_C2_OUTPUT) && (OutputCB2 ^ t)))
{
if(OutputCB2Func)
OutputCB2Func(user,t);
}
OutputCB2 = t;
}
ControlB = data;
update_6821_interrupts();
break;
}
}
u8 C6821::Read(int reg)
{
u8 ret;
switch(reg)
{
case c6821_ddra:
if(ControlA & CTRL_OUTPUT) //output selected
{
if(InputAFunc) //function specified to get input data?
InputA = InputAFunc(user);
ret = OutputA & DataA; //combine input and output data
ret |= InputA & ~DataA;
IRQA1 = 0; //clear irq data
IRQA2 = 0;
update_6821_interrupts();
if(ControlA & CTRL_C2_OUTPUT && //ca2 is output and strobe is on
(ControlA & CTRL_C2_SETMODE) == 0)
{
if(OutputCA2 && OutputCA2Func)//if output ca2 specified
OutputCA2Func(user,0); //send low signal
OutputCA2 = 0;
if(ControlA & CTRL_STROBE_E_RESET)
{
if(OutputCA2Func) //if output ca2 specified
OutputCA2Func(user,1); //send high signal
OutputCA2 = 1;
}
}
}
else //input selected, read data register
ret = DataA;
return(ret);
case c6821_ctrla:
if(InputCA1Func)
set_input_ca1(InputCA1Func(user));
if(InputCA2Func)
set_input_ca2(InputCA2Func(user));
ret = ControlA;
if(IRQA1)
ret |= 0x80;
if(IRQA2 && (ControlA & CTRL_C2_OUTPUT) == 0)
ret |= 0x40;
return(ret);
case c6821_ddrb:
if(ControlB & CTRL_OUTPUT) //output selected
{
if(InputBFunc) //function specified to get input data?
InputB = InputBFunc(user);
ret = OutputB & DataB; //combine input and output data
ret |= InputB & ~DataB;
if(IRQB1 &&
ControlB & CTRL_C2_OUTPUT &&
(ControlB & CTRL_C2_SETMODE) == 0 &&
(ControlB & CTRL_STROBE_E_RESET) == 0)
{
if(OutputCB2 == 0 && OutputCB2Func)
OutputCB2Func(user,1); //send high signal
OutputCB2 = 1;
}
IRQB1 = 0; //clear irq data
IRQB2 = 0;
update_6821_interrupts();
}
else //input selected, read data register
ret = DataB;
return(ret);
case c6821_ctrlb:
if(InputCB1Func)
set_input_cb1(InputCB1Func(user));
if(InputCB2Func)
set_input_cb2(InputCB2Func(user));
ret = ControlB;
if(IRQB1)
ret |= 0x80;
if(IRQB2 && (ControlB & CTRL_C2_OUTPUT) == 0)
ret |= 0x40;
return(ret);
}
return(0);
}
