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Diffstat (limited to 'src/devices/machine/7200fifo.cpp')
-rw-r--r--src/devices/machine/7200fifo.cpp55
1 files changed, 34 insertions, 21 deletions
diff --git a/src/devices/machine/7200fifo.cpp b/src/devices/machine/7200fifo.cpp
index a5af4967dc1..d411d7ededa 100644
--- a/src/devices/machine/7200fifo.cpp
+++ b/src/devices/machine/7200fifo.cpp
@@ -11,7 +11,7 @@
**********************************************************************/
#include "emu.h"
-#include "machine/7200fifo.h"
+#include "7200fifo.h"
DEFINE_DEVICE_TYPE(IDT7200, idt7200_device, "idt7200", "IDT7200 FIFO (256x9)")
@@ -22,13 +22,13 @@ DEFINE_DEVICE_TYPE(IDT7202, idt7202_device, "idt7202", "IDT7202 FIFO (1024x9)")
// fifo7200_device - constructor
//-------------------------------------------------
-fifo7200_device::fifo7200_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, int size)
- : device_t(mconfig, type, tag, owner, (uint32_t)0),
- m_ram_size(size),
- m_read_ptr(0), m_write_ptr(0), m_ef(0), m_ff(0), m_hf(0),
- m_ef_handler(*this),
- m_ff_handler(*this),
- m_hf_handler(*this)
+fifo7200_device::fifo7200_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, int size) :
+ device_t(mconfig, type, tag, owner, (uint32_t)0),
+ m_ram_size(size),
+ m_read_ptr(0), m_write_ptr(0), m_ef(0), m_ff(0), m_hf(0),
+ m_ef_handler(*this),
+ m_ff_handler(*this),
+ m_hf_handler(*this)
{
}
@@ -37,8 +37,8 @@ fifo7200_device::fifo7200_device(const machine_config &mconfig, device_type type
// idt7200_device - constructor
//-------------------------------------------------
-idt7200_device::idt7200_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
- : fifo7200_device(mconfig, IDT7200, tag, owner, 0x100)
+idt7200_device::idt7200_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+ fifo7200_device(mconfig, IDT7200, tag, owner, 0x100)
{
}
@@ -47,8 +47,8 @@ idt7200_device::idt7200_device(const machine_config &mconfig, const char *tag, d
// idt7201_device - constructor
//-------------------------------------------------
-idt7201_device::idt7201_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
- : fifo7200_device(mconfig, IDT7201, tag, owner, 0x200)
+idt7201_device::idt7201_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+ fifo7200_device(mconfig, IDT7201, tag, owner, 0x200)
{
}
@@ -57,8 +57,8 @@ idt7201_device::idt7201_device(const machine_config &mconfig, const char *tag, d
// idt7202_device - constructor
//-------------------------------------------------
-idt7202_device::idt7202_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
- : fifo7200_device(mconfig, IDT7202, tag, owner, 0x400)
+idt7202_device::idt7202_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+ fifo7200_device(mconfig, IDT7202, tag, owner, 0x400)
{
}
@@ -72,11 +72,6 @@ void fifo7200_device::device_start()
assert(m_ram_size > 1 && ~m_ram_size & 1);
m_buffer.resize(m_ram_size);
- // resolve callbacks
- m_ef_handler.resolve_safe();
- m_ff_handler.resolve_safe();
- m_hf_handler.resolve_safe();
-
// state save
save_item(NAME(m_buffer));
save_item(NAME(m_read_ptr));
@@ -132,7 +127,7 @@ void fifo7200_device::fifo_write(uint16_t data)
m_ff_handler(!m_ff);
}
- else if (((m_read_ptr + 1 + m_ram_size / 2) % m_ram_size) == m_write_ptr)
+ else if (!m_hf && (fifo_used() >= m_ram_size / 2))
{
m_hf = 1;
m_hf_handler(!m_hf);
@@ -166,12 +161,30 @@ uint16_t fifo7200_device::fifo_read()
m_ef_handler(!m_ef);
}
- else if (((m_read_ptr + m_ram_size / 2) % m_ram_size) == m_write_ptr)
+ else if (m_hf && (fifo_used() < m_ram_size / 2))
{
m_hf = 0;
m_hf_handler(!m_hf);
}
}
+ return ret;
+}
+
+int fifo7200_device::fifo_used()
+{
+ int ret = m_ram_size;
+
+ if (!m_ff)
+ {
+ if (m_write_ptr >= m_read_ptr)
+ {
+ ret = m_write_ptr - m_read_ptr;
+ }
+ else
+ {
+ ret = m_ram_size + m_write_ptr - m_read_ptr;
+ }
+ }
return ret;
}