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https://github.com/holub/mame
synced 2025-06-02 10:59:52 +03:00
Fixed Z80-PIO mode 3 interrupts, and mode 1 data writes.
meritm.c: Added scanline timer-based vblank interrupt to work around the broken V9938 interrupts. Megatouch games are now working again. [Curt Coder]
This commit is contained in:
Curt Coder
parent
a3da167012
commit
651caf7f1b
@ -111,12 +111,36 @@ static void check_interrupts(running_device *device)
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{
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pio_port *port = &z80pio->port[index];
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if (port->mode == MODE_BIT_CONTROL)
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{
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/* fetch input data (ignore output lines) */
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UINT8 data = (port->input & port->ior) | (port->output & ~port->ior);
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UINT8 mask = ~port->mask;
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int match = 0;
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data &= mask;
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if ((port->icw & 0x60) == 0 && data != mask) match = 1;
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else if ((port->icw & 0x60) == 0x20 && data != 0) match = 1;
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else if ((port->icw & 0x60) == 0x40 && data == 0) match = 1;
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else if ((port->icw & 0x60) == 0x60 && data == mask) match = 1;
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if (!port->match && match)
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{
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/* trigger interrupt */
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port->ip = 1;
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if (LOG) logerror("Z80PIO '%s' Port %c Interrupt Pending\n", device->tag.cstr(), 'A' + index);
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}
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port->match = match;
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}
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if (port->ie && port->ip && !port->ius)
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{
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state = ASSERT_LINE;
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}
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}
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devcb_call_write_line(&z80pio->out_int_func, state);
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}
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@ -254,6 +278,14 @@ WRITE8_DEVICE_HANDLER( z80pio_c_w )
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case 0x07: /* set interrupt control word */
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port->icw = data;
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if (LOG)
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{
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logerror("Z80PIO '%s' Port %c Interrupt Enable: %u\n", device->tag.cstr(), 'A' + index, BIT(data, 7));
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logerror("Z80PIO '%s' Port %c Logic: %s\n", device->tag.cstr(), 'A' + index, BIT(data, 6) ? "AND" : "OR");
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logerror("Z80PIO '%s' Port %c Active %s\n", device->tag.cstr(), 'A' + index, BIT(data, 5) ? "High" : "Low");
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logerror("Z80PIO '%s' Port %c Mask Follows: %u\n", device->tag.cstr(), 'A' + index, BIT(data, 4));
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}
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if (port->icw & ICW_MASK_FOLLOWS)
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{
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/* disable interrupts until mask is written */
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@ -269,6 +301,11 @@ WRITE8_DEVICE_HANDLER( z80pio_c_w )
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/* next word is mask control */
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port->next_control_word = MASK;
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}
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else
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{
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/* monitor all bits */
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port->mask = 0;
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}
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break;
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case 0x03: /* set interrupt enable flip-flop */
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@ -394,7 +431,8 @@ WRITE8_DEVICE_HANDLER( z80pio_d_w )
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break;
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case MODE_INPUT:
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/* do nothing */
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/* latch output data */
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port->output = data;
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break;
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case MODE_BIDIRECTIONAL:
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@ -497,60 +535,6 @@ READ8_DEVICE_HANDLER( z80pio_pa_r )
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return data;
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}
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/*-------------------------------------------------
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check_equation - check bit logic equation
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-------------------------------------------------*/
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static void check_equation(running_device *device, int index, UINT8 data)
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{
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z80pio_t *z80pio = get_safe_token(device);
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pio_port *port = &z80pio->port[index];
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if (port->mask == 0xff) return;
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int bit;
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int match = 0;
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int edge = (port->icw & ICW_HIGH) ? 1 : 0;
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UINT8 mask = port->mask;
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UINT8 ior = port->ior;
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UINT8 old_data = port->input;
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if (old_data == data) return;
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for (bit = 0; bit < 8; bit++)
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{
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if (BIT(mask, bit)) continue; /* masked out */
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if (!BIT(ior, bit)) continue; /* output bit */
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if ((BIT(old_data, bit) ^ edge) && !(BIT(data, bit) ^ edge)) /* falling edge */
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{
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/* logic equation is true, until proven otherwise */
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match = 1;
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if (LOG) logerror("Z80PIO '%s' Port %c Edge Transition detected on bit %u, data %02x %02x\n", device->tag.cstr(), 'A' + index, bit, old_data, data);
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}
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else if (port->icw & ICW_AND)
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{
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/* all bits must match in AND mode, so logic equation is false */
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match = 0;
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break;
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}
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}
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if (!port->match && match) /* rising edge */
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{
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/* latch data */
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port->input = data;
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/* trigger interrupt only once */
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trigger_interrupt(device, index);
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}
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port->match = match;
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}
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/*-------------------------------------------------
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z80pio_pa_w - port A write
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-------------------------------------------------*/
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@ -562,7 +546,9 @@ WRITE8_DEVICE_HANDLER( z80pio_pa_w )
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if (port->mode == MODE_BIT_CONTROL)
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{
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check_equation(device, PORT_A, data);
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/* latch data */
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port->input = data;
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check_interrupts(device);
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}
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}
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@ -602,7 +588,9 @@ WRITE8_DEVICE_HANDLER( z80pio_pb_w )
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if (port->mode == MODE_BIT_CONTROL)
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{
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check_equation(device, PORT_B, data);
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/* latch data */
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port->input = data;
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check_interrupts(device);
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}
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}
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@ -760,11 +748,12 @@ static int z80pio_irq_ack(running_device *device)
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/* clear interrupt pending flag */
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port->ip = 0;
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check_interrupts(device);
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/* set interrupt under service flag */
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port->ius = 1;
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check_interrupts(device);
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return port->vector;
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}
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}
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@ -854,9 +843,6 @@ static DEVICE_RESET( z80pio )
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/* set mode 1 */
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set_mode(device, index, MODE_INPUT);
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/* reset port mask registers */
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port->mask = 0;
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/* reset interrupt enable flip-flops */
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port->icw &= ~ICW_ENABLE_INT;
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port->ie = 0;
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@ -299,7 +299,7 @@ static int meritm_touch_coord_transform(running_machine *machine, int *touch_x,
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*
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*************************************/
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static int meritm_vint = 0x00;
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static int meritm_vint = 0x18;
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static int meritm_interrupt_vdp0_state = 0;
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static int meritm_interrupt_vdp1_state = 0;
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static bitmap_t *vdp0_bitmap, *vdp1_bitmap;
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@ -317,32 +317,14 @@ static INTERRUPT_GEN( meritm_interrupt )
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static void meritm_vdp0_interrupt(running_machine *machine, int i)
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{
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if ( meritm_interrupt_vdp0_state != i )
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{
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meritm_interrupt_vdp0_state = i;
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if (i)
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meritm_vint &= ~0x08;
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else
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meritm_vint |= 0x08;
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if(i)
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z80pio_pa_w(meritm_z80pio[0], 0, meritm_vint);
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}
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/* this is not used as the v9938 interrupt callbacks are broken
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interrupts seem to be fired quite randomly */
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}
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static void meritm_vdp1_interrupt(running_machine *machine, int i)
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{
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if ( meritm_interrupt_vdp1_state != i )
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{
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meritm_interrupt_vdp1_state = i;
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if (i)
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meritm_vint &= ~0x10;
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else
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meritm_vint |= 0x10;
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if(i)
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z80pio_pa_w(meritm_z80pio[0], 0, meritm_vint);
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}
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/* this is not used as the v9938 interrupt callbacks are broken
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interrupts seem to be fired quite randomly */
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}
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static int layer0_enabled, layer1_enabled;
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@ -1051,6 +1033,20 @@ static NVRAM_HANDLER(meritm_crt260)
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#define MSX2_VISIBLE_XBORDER_PIXELS 8 * 2
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#define MSX2_VISIBLE_YBORDER_PIXELS 14 * 2
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static TIMER_DEVICE_CALLBACK( vblank_start_tick )
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{
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/* this is a workaround to signal the v9938 vblank interrupt correctly */
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meritm_vint = 0x08;
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z80pio_pa_w(meritm_z80pio[0], 0, meritm_vint);
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}
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static TIMER_DEVICE_CALLBACK( vblank_end_tick )
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{
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/* this is a workaround to signal the v9938 vblank interrupt correctly */
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meritm_vint = 0x18;
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z80pio_pa_w(meritm_z80pio[0], 0, meritm_vint);
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}
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static MACHINE_DRIVER_START(meritm_crt250)
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MDRV_CPU_ADD("maincpu", Z80, SYSTEM_CLK/6)
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MDRV_CPU_PROGRAM_MAP(meritm_crt250_map)
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@ -1065,6 +1061,9 @@ static MACHINE_DRIVER_START(meritm_crt250)
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MDRV_Z80PIO_ADD( "z80pio_0", SYSTEM_CLK/6, meritm_audio_pio_intf )
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MDRV_Z80PIO_ADD( "z80pio_1", SYSTEM_CLK/6, meritm_io_pio_intf )
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MDRV_TIMER_ADD_SCANLINE("vblank_start", vblank_start_tick, "screen", 259, 262)
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MDRV_TIMER_ADD_SCANLINE("vblank_end", vblank_end_tick, "screen", 262, 262)
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MDRV_NVRAM_HANDLER(generic_0fill)
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MDRV_VIDEO_ATTRIBUTES(VIDEO_UPDATE_BEFORE_VBLANK)
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