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Diffstat (limited to 'src/devices/cpu/m6502/st2205u.cpp')
-rw-r--r--src/devices/cpu/m6502/st2205u.cpp193
1 files changed, 160 insertions, 33 deletions
diff --git a/src/devices/cpu/m6502/st2205u.cpp b/src/devices/cpu/m6502/st2205u.cpp
index 58b887a3aea..5ebf6236f28 100644
--- a/src/devices/cpu/m6502/st2205u.cpp
+++ b/src/devices/cpu/m6502/st2205u.cpp
@@ -42,6 +42,8 @@ st2205u_device::st2205u_device(const machine_config &mconfig, const char *tag, d
true)
, m_btc(0)
, m_tc_12bit{0}
+ , m_count_12bit{0}
+ , m_timer_12bit{nullptr}
, m_t4c(0)
, m_tien(0)
, m_dac_fifo{{0}}
@@ -78,11 +80,17 @@ void st2205u_device::device_start()
intf->irq_service = false;
intf->ram = make_unique_clear<u8[]>(0x8000);
+ m_timer_12bit[0] = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(st2205u_device::t0_interrupt), this));
+ m_timer_12bit[1] = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(st2205u_device::t1_interrupt), this));
+ m_timer_12bit[2] = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(st2205u_device::t2_interrupt), this));
+ m_timer_12bit[3] = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(st2205u_device::t3_interrupt), this));
+
init_base_timer(0x0040);
init_lcd_timer(0x0080);
save_item(NAME(m_btc));
save_item(NAME(m_tc_12bit));
+ save_item(NAME(m_count_12bit));
save_item(NAME(m_t4c));
save_item(NAME(m_tien));
save_item(NAME(m_dac_fifo));
@@ -134,6 +142,8 @@ void st2205u_device::device_start()
state_add(ST_BTEN, "BTEN", m_bten, [this](u8 data) { bten_w(data); });
state_add(ST_BTSR, "BTREQ", m_btsr);
state_add(ST_BTC, "BTC", m_btc);
+ for (int i = 0; i < 4; i++)
+ state_add(ST_T0C + i, string_format("T%dC", i).c_str(), m_tc_12bit[i]);
state_add(ST_T4C, "T4C", m_t4c);
state_add(ST_TIEN, "TIEN", m_tien);
for (int i = 0; i < 4; i++)
@@ -190,6 +200,9 @@ void st2205u_device::device_reset()
m_btc = 0;
std::fill(std::begin(m_tc_12bit), std::end(m_tc_12bit), 0);
+ std::fill(std::begin(m_count_12bit), std::end(m_count_12bit), 0);
+ for (auto &timer : m_timer_12bit)
+ timer->adjust(attotime::never);
m_t4c = 0;
m_tien = 0;
@@ -391,39 +404,6 @@ void st2205u_device::btc_w(u8 data)
m_btc = data;
}
-u8 st2205u_device::tc_12bit_r(offs_t offset)
-{
- return (m_tc_12bit[offset >> 1] >> (BIT(offset, 0) ? 8 : 0)) & 0x00ff;
-}
-
-void st2205u_device::tc_12bit_w(offs_t offset, u8 data)
-{
- if (BIT(offset, 0))
- m_tc_12bit[offset >> 1] = (m_tc_12bit[offset >> 1] & 0x00ff) | u16(data) << 8;
- else
- m_tc_12bit[offset >> 1] = (m_tc_12bit[offset >> 1] & 0xff00) | data;
-}
-
-u8 st2205u_device::t4c_r()
-{
- return m_t4c;
-}
-
-void st2205u_device::t4c_w(u8 data)
-{
- m_t4c = data;
-}
-
-u8 st2205u_device::tien_r()
-{
- return m_tien;
-}
-
-void st2205u_device::tien_w(u8 data)
-{
- m_tien = data;
-}
-
u8 st2205u_device::psg_r(offs_t offset)
{
u8 index = 0;
@@ -487,10 +467,157 @@ void st2205u_device::volm_w(offs_t offset, u8 data)
void st2205u_device::st2xxx_tclk_start()
{
+ for (int t = 0; t < 4; t++)
+ if (BIT(m_tien, t) && (m_tc_12bit[t] & 0x7000) < 0x6000)
+ timer_start_from_tclk(t);
}
void st2205u_device::st2xxx_tclk_stop()
{
+ for (int t = 0; t < 4; t++)
+ {
+ if (BIT(m_tien, t) && (m_tc_12bit[t] & 0x7000) < 0x6000)
+ {
+ m_count_12bit[t] = timer_12bit_count(t);
+ m_timer_12bit[t]->adjust(attotime::never);
+ }
+ }
+}
+
+u32 st2205u_device::tclk_pres_div(u8 mode) const
+{
+ assert(mode < 6);
+ if (mode < 3)
+ return 2 << mode;
+ else if (mode == 3)
+ return 32;
+ else if (mode == 4)
+ return 1024;
+ else
+ return 4096;
+}
+
+TIMER_CALLBACK_MEMBER(st2205u_device::t0_interrupt)
+{
+ m_ireq |= 0x0002;
+ update_irq_state();
+ timer_12bit_process(0);
+}
+
+TIMER_CALLBACK_MEMBER(st2205u_device::t1_interrupt)
+{
+ m_ireq |= 0x0004;
+ update_irq_state();
+ timer_12bit_process(1);
+}
+
+TIMER_CALLBACK_MEMBER(st2205u_device::t2_interrupt)
+{
+ m_ireq |= 0x0008;
+ update_irq_state();
+ timer_12bit_process(2);
+}
+
+TIMER_CALLBACK_MEMBER(st2205u_device::t3_interrupt)
+{
+ m_ireq |= 0x0010;
+ update_irq_state();
+ timer_12bit_process(3);
+}
+
+void st2205u_device::timer_12bit_process(int t)
+{
+ // Bit 7 of TnCH allows auto-reload
+ m_count_12bit[t] = BIT(m_tc_12bit[t], 15) ? m_tc_12bit[t] & 0x0fff : 0;
+
+ u8 tck = (m_tc_12bit[t] & 0x7000) >> 12;
+ if (tck < 6)
+ m_timer_12bit[t]->adjust(cycles_to_attotime((0x1000 - m_count_12bit[t]) * tclk_pres_div(tck)));
+ else if (tck == 7 && BIT(t, 0))
+ m_timer_12bit[t]->adjust(attotime::from_ticks(0x1000 - m_count_12bit[t], 32768));
+
+ // TODO: BGRCK & INTX sources
+}
+
+u16 st2205u_device::timer_12bit_count(int t) const
+{
+ u16 count = m_count_12bit[t];
+ if (BIT(m_tien, t))
+ {
+ u8 tck = (m_tc_12bit[t] & 0x7000) >> 12;
+ if (BIT(m_prs, 6) && tck < 6)
+ count = 0x0fff - (attotime_to_cycles(m_timer_12bit[t]->remaining()) / tclk_pres_div(tck));
+ else if (tck == 7 && BIT(t, 0))
+ count = 0x0fff - m_timer_12bit[t]->remaining().as_ticks(32768);
+ }
+
+ return count & 0x0fff;
+}
+
+void st2205u_device::timer_start_from_tclk(int t)
+{
+ u32 div = tclk_pres_div((m_tc_12bit[t] & 0x7000) >> 12);
+ m_timer_12bit[t]->adjust(cycles_to_attotime((0x0fff - m_count_12bit[t]) * div + div - (pres_count() & (div - 1))));
+}
+
+void st2205u_device::timer_start_from_oscx(int t)
+{
+ m_timer_12bit[t]->adjust(attotime::from_ticks(0x1000 - m_count_12bit[t], 32768));
+}
+
+u8 st2205u_device::tc_12bit_r(offs_t offset)
+{
+ if (BIT(offset, 0))
+ return (timer_12bit_count(offset >> 1) | (m_tc_12bit[offset >> 1] & 0xf000)) >> 8;
+ else
+ return timer_12bit_count(offset >> 1) & 0x00ff;
+}
+
+void st2205u_device::tc_12bit_w(offs_t offset, u8 data)
+{
+ if (BIT(offset, 0))
+ m_tc_12bit[offset >> 1] = (m_tc_12bit[offset >> 1] & 0x00ff) | u16(data) << 8;
+ else
+ m_tc_12bit[offset >> 1] = (m_tc_12bit[offset >> 1] & 0xff00) | data;
+}
+
+u8 st2205u_device::t4c_r()
+{
+ return m_t4c;
+}
+
+void st2205u_device::t4c_w(u8 data)
+{
+ m_t4c = data;
+}
+
+u8 st2205u_device::tien_r()
+{
+ return m_tien;
+}
+
+void st2205u_device::tien_w(u8 data)
+{
+ for (int t = 0; t < 4; t++)
+ {
+ if (BIT(m_tien, t) && !BIT(data, t))
+ {
+ m_count_12bit[t] = timer_12bit_count(t);
+ m_timer_12bit[t]->adjust(attotime::never);
+ }
+ else if (!BIT(m_tien, t) && BIT(data, t))
+ {
+ m_count_12bit[t] = m_tc_12bit[t] & 0x0fff;
+
+ u8 tck = (m_tc_12bit[t] & 0x7000) >> 12;
+ if (BIT(m_prs, 6) && tck < 6)
+ timer_start_from_tclk(t);
+ else if (tck == 7 && BIT(t, 0))
+ timer_start_from_oscx(t);
+ }
+ }
+
+ m_tien = data;
}
unsigned st2205u_device::st2xxx_lfr_clocks() const