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author AJR <ajrhacker@users.noreply.github.com>2021-05-06 13:30:47 -0400
committer AJR <ajrhacker@users.noreply.github.com>2021-05-06 13:30:50 -0400
commitfc77338e37b416d1fbf1f17409a81aa8039d3fed (patch)
treeabac5bf8981dbb6a3afcdd112e1d01351e708620
parent9ea37cb4d18aee7bcbb030dba38e01d3885e253a (diff)
m5074x: Add port pullup configuration
-rw-r--r--src/devices/cpu/m6502/m5074x.cpp31
-rw-r--r--src/devices/cpu/m6502/m5074x.h3
2 files changed, 18 insertions, 16 deletions
diff --git a/src/devices/cpu/m6502/m5074x.cpp b/src/devices/cpu/m6502/m5074x.cpp
index 46e6fffc9ae..5df0e863a0c 100644
--- a/src/devices/cpu/m6502/m5074x.cpp
+++ b/src/devices/cpu/m6502/m5074x.cpp
@@ -57,6 +57,7 @@ m5074x_device::m5074x_device(const machine_config &mconfig, device_type type, co
m_tmrxlatch(0),
m_last_all_ints(0)
{
+ std::fill(std::begin(m_pullups), std::end(m_pullups), 0);
}
//-------------------------------------------------
@@ -315,7 +316,7 @@ uint8_t m5074x_device::ports_r(offs_t offset)
return m_ddrs[3];
case 0xa:
- return read_port(4);
+ return read_port(4) & 0x0f;
case 0xb:
return m_ddrs[4];
@@ -329,53 +330,53 @@ void m5074x_device::ports_w(offs_t offset, uint8_t data)
switch (offset)
{
case 0: // p0
- send_port(0, data & m_ddrs[0]);
+ send_port(0, (data & m_ddrs[0]) | (m_pullups[0] & ~m_ddrs[0]));
m_ports[0] = data;
break;
case 1: // p0 ddr
- send_port(0, m_ports[0] & data);
+ send_port(0, (m_ports[0] & data) | (m_pullups[0] & ~data));
m_ddrs[0] = data;
break;
case 2: // p1
- send_port(1, data & m_ddrs[1]);
+ send_port(1, (data & m_ddrs[1]) | (m_pullups[1] & ~m_ddrs[1]));
m_ports[1] = data;
break;
case 3: // p1 ddr
- send_port(1, m_ports[1] & data);
+ send_port(1, (m_ports[1] & data) | (m_pullups[1] & ~data));
m_ddrs[1] = data;
break;
case 4: // p2
- send_port(2, data & m_ddrs[2]);
+ send_port(2, (data & m_ddrs[2]) | (m_pullups[2] & ~m_ddrs[2]));
m_ports[2] = data;
break;
case 5: // p2 ddr
- send_port(2, m_ports[2] & data);
+ send_port(2, (m_ports[2] & data) | (m_pullups[2] & ~data));
m_ddrs[2] = data;
break;
case 8: // p3
- send_port(3, data & m_ddrs[3]);
+ send_port(3, (data & m_ddrs[3]) | (m_pullups[3] & ~m_ddrs[3]));
m_ports[3] = data;
break;
case 9: // p3 ddr
- send_port(3, m_ports[3] & data);
+ send_port(3, (m_ports[3] & data) | (m_pullups[3] & ~data));
m_ddrs[3] = data;
break;
- case 0xa: // p4
- send_port(4, data & m_ddrs[4]);
- m_ports[4] = data;
+ case 0xa: // p4 (4-bit open drain)
+ send_port(4, (data & m_ddrs[4] & 0x0f) | (m_pullups[4] & ~m_ddrs[4]));
+ m_ports[4] = data & 0x0f;
break;
case 0xb: // p4 ddr
- send_port(4, m_ports[4] & data);
- m_ddrs[4] = data;
+ send_port(4, (m_ports[4] & data & 0x0f) | (m_pullups[4] & ~data));
+ m_ddrs[4] = data & 0x0f;
break;
}
}
@@ -496,7 +497,7 @@ void m50753_device::m50753_map(address_map &map)
map(0x00e0, 0x00eb).rw(FUNC(m50753_device::ports_r), FUNC(m50753_device::ports_w));
map(0x00ee, 0x00ee).r(FUNC(m50753_device::in_r));
map(0x00ef, 0x00ef).r(FUNC(m50753_device::ad_r));
- map(0x00f2, 0x00f2).w(FUNC(m50753_device::ad_start_w));
+ map(0x00f2, 0x00f2).nopr().w(FUNC(m50753_device::ad_start_w));
map(0x00f3, 0x00f3).rw(FUNC(m50753_device::ad_control_r), FUNC(m50753_device::ad_control_w));
map(0x00f5, 0x00f5).rw(FUNC(m50753_device::pwm_control_r), FUNC(m50753_device::pwm_control_w));
map(0x00f9, 0x00ff).rw(FUNC(m50753_device::tmrirq_r), FUNC(m50753_device::tmrirq_w));
diff --git a/src/devices/cpu/m6502/m5074x.h b/src/devices/cpu/m6502/m5074x.h
index 8e9a037708a..b7ce310bd6e 100644
--- a/src/devices/cpu/m6502/m5074x.h
+++ b/src/devices/cpu/m6502/m5074x.h
@@ -40,6 +40,7 @@ public:
template <std::size_t Bit> auto read_p() { return m_read_p[Bit].bind(); }
template <std::size_t Bit> auto write_p() { return m_write_p[Bit].bind(); }
+ template <std::size_t Bit> void set_pullups(u8 mask) { m_pullups[Bit] = mask; }
uint8_t ports_r(offs_t offset);
void ports_w(offs_t offset, uint8_t data);
@@ -72,7 +73,7 @@ protected:
devcb_read8::array<5> m_read_p;
devcb_write8::array<5> m_write_p;
- uint8_t m_ports[5], m_ddrs[5];
+ uint8_t m_ports[5], m_ddrs[5], m_pullups[5];
uint8_t m_intctrl, m_tmrctrl;
uint8_t m_tmr12pre, m_tmr1, m_tmr2, m_tmrxpre, m_tmrx;
uint8_t m_tmr1latch, m_tmr2latch, m_tmrxlatch;