mirror of
https://github.com/holub/mame
synced 2025-04-22 16:31:49 +03:00
Allow reading from port A in output mode. Add a separate bit for timer 1 PB7 toggling rather than changing the PB register directly. Don't clear the SR register on reset. Clears pcr & acr at construct time, in case something sets one of the handshaking lines before we've started. Use a separate variable for the latched inputs and the current inputs. Consolidated the input and output code. [smf]
This commit is contained in:
smf-
parent
4830ec15d8
commit
91a1d90bb6
@ -156,12 +156,14 @@ via6522_device::via6522_device(const machine_config &mconfig, const char *tag, d
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m_cb1_handler(*this),
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m_cb2_handler(*this),
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m_irq_handler(*this),
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m_in_a(0),
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m_in_a(0xff),
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m_in_ca1(0),
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m_in_ca2(0),
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m_in_b(0),
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m_in_cb1(0),
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m_in_cb2(0),
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m_pcr(0),
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m_acr(0),
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m_irq(CLEAR_LINE)
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{
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}
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@ -186,12 +188,13 @@ void via6522_device::device_start()
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m_t1lh = 0xb5; /* ports are not written by kernel! */
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m_t2ll = 0xff; /* taken from vice */
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m_t2lh = 0xff;
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m_sr = 0;
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m_time2 = m_time1 = machine().time();
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m_t1 = timer_alloc(TIMER_T1);
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m_t2 = timer_alloc(TIMER_T2);
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m_ca2_timer = timer_alloc(TIMER_CA2);
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m_shift_timer = timer_alloc(TIMER_SHIFT);
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m_pcr = 0;
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/* Default clock is from CPU1 */
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if (clock() == 0)
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@ -206,6 +209,7 @@ void via6522_device::device_start()
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save_item(NAME(m_out_a));
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save_item(NAME(m_out_ca2));
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save_item(NAME(m_ddr_a));
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save_item(NAME(m_latch_a));
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save_item(NAME(m_in_b));
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save_item(NAME(m_in_cb1));
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save_item(NAME(m_in_cb2));
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@ -213,6 +217,7 @@ void via6522_device::device_start()
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save_item(NAME(m_out_cb1));
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save_item(NAME(m_out_cb2));
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save_item(NAME(m_ddr_b));
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save_item(NAME(m_latch_b));
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save_item(NAME(m_t1cl));
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save_item(NAME(m_t1ch));
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save_item(NAME(m_t1ll));
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@ -228,6 +233,7 @@ void via6522_device::device_start()
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save_item(NAME(m_ifr));
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save_item(NAME(m_irq));
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save_item(NAME(m_t1_active));
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save_item(NAME(m_t1_pb7));
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save_item(NAME(m_t2_active));
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save_item(NAME(m_shift_counter));
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}
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@ -252,15 +258,17 @@ void via6522_device::device_reset()
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m_t2cl = 0;
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m_t2ch = 0;
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m_sr = 0;
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m_pcr = 0;
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m_acr = 0;
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m_ier = 0;
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m_ifr = 0;
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m_t1_active = 0;
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m_t1_pb7 = 1;
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m_t2_active = 0;
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m_shift_counter = 0;
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output_pa();
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output_pb();
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m_ca2_handler(m_out_ca2);
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m_cb1_handler(m_out_cb1);
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m_cb2_handler(m_out_cb2);
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@ -387,25 +395,19 @@ void via6522_device::device_timer(emu_timer &timer, device_timer_id id, int para
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case TIMER_T1:
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if (T1_CONTINUOUS (m_acr))
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{
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if (T1_SET_PB7(m_acr))
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{
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m_out_b ^= 0x80;
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}
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m_t1_pb7 = !m_t1_pb7;
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m_t1->adjust(clocks_to_attotime(TIMER1_VALUE + IFR_DELAY));
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}
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else
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{
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if (T1_SET_PB7(m_acr))
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{
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m_out_b |= 0x80;
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}
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m_t1_pb7 = 1;
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m_t1_active = 0;
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m_time1 = machine().time();
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}
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if (m_ddr_b)
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if (T1_SET_PB7(m_acr))
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | (m_ddr_b ^ 0xff);
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m_out_b_handler(write_data);
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output_pb();
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}
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if (!(m_ifr & INT_T1))
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@ -431,6 +433,52 @@ void via6522_device::device_timer(emu_timer &timer, device_timer_id id, int para
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}
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}
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UINT8 via6522_device::input_pa()
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{
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/// TODO: REMOVE THIS
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if (!m_in_a_handler.isnull())
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{
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m_in_a = m_in_a_handler(0);
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}
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/* combine input and output values */
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return m_in_a & (m_out_a | ~m_ddr_a);
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}
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void via6522_device::output_pa()
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{
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UINT8 write_data = (m_out_a & m_ddr_a) | ~m_ddr_a;
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m_out_a_handler(write_data);
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}
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UINT8 via6522_device::input_pb()
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{
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/// TODO: REMOVE THIS
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if (m_ddr_b != 0xff && !m_in_b_handler.isnull())
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{
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m_in_b = m_in_b_handler(0);
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}
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UINT8 data = (m_in_b & ~m_ddr_b) | (m_out_b & m_ddr_b);
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if (T1_SET_PB7(m_acr))
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{
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data = (data & 0x7f) | (m_t1_pb7 << 7);
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}
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return data;
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}
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void via6522_device::output_pb()
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | ~m_ddr_b;
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if (T1_SET_PB7(m_acr))
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write_data = (write_data & 0x7f) | (m_t1_pb7 << 7);
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m_out_b_handler(write_data);
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}
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/*-------------------------------------------------
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via_r - CPU interface for VIA read
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-------------------------------------------------*/
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@ -447,54 +495,25 @@ READ8_MEMBER( via6522_device::read )
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/* update the input */
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if (PB_LATCH_ENABLE(m_acr) == 0)
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{
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if (m_ddr_b != 0xff)
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{
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if (!m_in_b_handler.isnull())
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{
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m_in_b = m_in_b_handler(0);
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}
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else
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{
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logerror("%s:6522VIA chip %s: Port B is being read but has no handler\n", machine().describe_context(), tag());
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}
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}
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}
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CLR_PB_INT();
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/* combine input and output values, hold DDRB bit 7 high if T1_SET_PB7 */
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if (T1_SET_PB7(m_acr))
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{
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val = (m_out_b & (m_ddr_b | 0x80)) | (m_in_b & ~(m_ddr_b | 0x80));
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val = input_pb();
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}
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else
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{
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val = (m_out_b & m_ddr_b) + (m_in_b & ~m_ddr_b);
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val = m_latch_b;
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}
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CLR_PB_INT();
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break;
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case VIA_PA:
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/* update the input */
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if (PA_LATCH_ENABLE(m_acr) == 0)
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{
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if (m_ddr_a != 0xff)
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{
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if (!m_in_a_handler.isnull())
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{
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m_in_a = m_in_a_handler(0);
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}
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else
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{
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logerror("%s:6522VIA chip %s: Port A is being read but has no handler\n", machine().describe_context(), tag());
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}
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}
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/* combine input and output values */
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val = (m_out_a & m_ddr_a) + (m_in_a & ~m_ddr_a);
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val = input_pa();
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}
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else
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{
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val = m_in_a;
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val = m_latch_a;
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}
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CLR_PA_INT();
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@ -514,18 +533,12 @@ READ8_MEMBER( via6522_device::read )
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/* update the input */
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if (PA_LATCH_ENABLE(m_acr) == 0)
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{
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if (!m_in_a_handler.isnull())
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{
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m_in_a = m_in_a_handler(0);
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}
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else
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{
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logerror("%s:6522VIA chip %s: Port A is being read but has no handler\n", machine().describe_context(), tag());
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}
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val = input_pa();
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}
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else
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{
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val = m_latch_a;
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}
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/* combine input and output values */
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val = (m_out_a & m_ddr_a) + (m_in_a & ~m_ddr_a);
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break;
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case VIA_DDRB:
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@ -635,15 +648,11 @@ WRITE8_MEMBER( via6522_device::write )
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switch (offset)
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{
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case VIA_PB:
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if (T1_SET_PB7(m_acr))
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m_out_b = (m_out_b & 0x80) | (data & 0x7f);
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else
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m_out_b = data;
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m_out_b = data;
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if (m_ddr_b)
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if (m_ddr_b != 0)
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | (m_ddr_b ^ 0xff);
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m_out_b_handler(write_data);
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output_pb();
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}
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CLR_PB_INT();
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@ -658,10 +667,9 @@ WRITE8_MEMBER( via6522_device::write )
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case VIA_PA:
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m_out_a = data;
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if (m_ddr_a)
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if (m_ddr_a != 0)
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{
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UINT8 write_data = (m_out_a & m_ddr_a) | (m_ddr_a ^ 0xff);
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m_out_a_handler(write_data);
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output_pa();
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}
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CLR_PA_INT();
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@ -680,39 +688,28 @@ WRITE8_MEMBER( via6522_device::write )
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case VIA_PANH:
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m_out_a = data;
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if (m_ddr_a)
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if (m_ddr_a != 0)
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{
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UINT8 write_data = (m_out_a & m_ddr_a) | (m_ddr_a ^ 0xff);
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m_out_a_handler(write_data);
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output_pa();
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}
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break;
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case VIA_DDRB:
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/* EHC 03/04/2000 - If data direction changed, present output on the lines */
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if ( data != m_ddr_b )
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{
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m_ddr_b = data;
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//if (m_ddr_b)
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | (m_ddr_b ^ 0xff);
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m_out_b_handler(write_data);
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}
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output_pb();
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}
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break;
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case VIA_DDRA:
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/* EHC 03/04/2000 - If data direction changed, present output on the lines */
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if ( data != m_ddr_a )
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if (m_ddr_a != data)
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{
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m_ddr_a = data;
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//if (m_ddr_a)
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{
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UINT8 write_data = (m_out_a & m_ddr_a) | (m_ddr_a ^ 0xff);
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m_out_a_handler(write_data);
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}
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output_pa();
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}
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break;
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@ -732,16 +729,13 @@ WRITE8_MEMBER( via6522_device::write )
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clear_int(INT_T1);
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m_t1_pb7 = 0;
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if (T1_SET_PB7(m_acr))
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{
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m_out_b &= 0x7f;
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//if (m_ddr_b)
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | (m_ddr_b ^ 0xff);
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m_out_b_handler(write_data);
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}
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output_pb();
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}
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m_t1->adjust(clocks_to_attotime(TIMER1_VALUE + IFR_DELAY));
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m_t1_active = 1;
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break;
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@ -808,23 +802,9 @@ WRITE8_MEMBER( via6522_device::write )
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{
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UINT16 counter1 = get_counter1_value();
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m_acr = data;
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if (T1_SET_PB7(m_acr))
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{
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if (m_t1_active)
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{
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m_out_b &= ~0x80;
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}
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else
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{
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m_out_b |= 0x80;
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}
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//if (m_ddr_b)
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{
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UINT8 write_data = (m_out_b & m_ddr_b) | (m_ddr_b ^ 0xff);
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m_out_b_handler(write_data);
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}
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}
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output_pb();
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if (T1_CONTINUOUS(data))
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{
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m_t1->adjust(clocks_to_attotime(counter1 + IFR_DELAY));
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@ -896,14 +876,7 @@ WRITE_LINE_MEMBER( via6522_device::write_ca1 )
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{
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if (PA_LATCH_ENABLE(m_acr))
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{
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if (!m_in_a_handler.isnull())
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{
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m_in_a = m_in_a_handler(0);
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}
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else
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{
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logerror("%s:6522VIA chip %s: Port A is being read but has no handler\n", machine().describe_context(), tag());
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}
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m_latch_a = input_pa();
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}
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set_int(INT_CA1);
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@ -963,14 +936,7 @@ WRITE_LINE_MEMBER( via6522_device::write_cb1 )
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{
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if (PB_LATCH_ENABLE(m_acr))
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{
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if (!m_in_b_handler.isnull())
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{
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m_in_b = m_in_b_handler(0);
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}
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else
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{
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logerror("%s:6522VIA chip %s: Port B is being read but has no handler\n", machine().describe_context(), tag());
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}
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m_latch_b = input_pb();
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}
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if (SO_EXT_CONTROL(m_acr))
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@ -144,6 +144,11 @@ private:
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void write_pa(int line, int state);
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void write_pb(int line, int state);
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UINT8 input_pa();
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void output_pa();
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UINT8 input_pb();
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void output_pb();
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// TODO: REMOVE THESE
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devcb2_read8 m_in_a_handler;
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devcb2_read8 m_in_b_handler;
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@ -163,6 +168,7 @@ private:
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UINT8 m_out_a;
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UINT8 m_out_ca2;
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UINT8 m_ddr_a;
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UINT8 m_latch_a;
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UINT8 m_in_b;
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UINT8 m_in_cb1;
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@ -171,11 +177,14 @@ private:
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UINT8 m_out_cb1;
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UINT8 m_out_cb2;
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UINT8 m_ddr_b;
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UINT8 m_latch_b;
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UINT8 m_t1cl;
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UINT8 m_t1ch;
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UINT8 m_t1ll;
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UINT8 m_t1lh;
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int m_t1_pb7;
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UINT8 m_t2cl;
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UINT8 m_t2ch;
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UINT8 m_t2ll;
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