add device: mb87078 digital volume controller, used by taito f3

makefile.burn_rules

@@ -92,7 +92,7 @@ depobj	:= 	$(drvobj) \
 			burn.o burn_gun.o burn_led.o burn_shift.o burn_memory.o burn_sound.o burn_sound_c.o cheat.o debug_track.o hiscore.o load.o tilemap_generic.o \
 			tiles_generic.o timer.o vector.o \
 			\
-			6821pia.o 8255ppi.o 8257dma.o eeprom.o gaelco_crypt.o joyprocess.o nb1414m4.o nb1414m4_8bit.o nmk004.o nmk112.o kaneko_tmap.o mermaid.o \
+			6821pia.o 8255ppi.o 8257dma.o eeprom.o gaelco_crypt.o joyprocess.o nb1414m4.o nb1414m4_8bit.o nmk004.o nmk112.o kaneko_tmap.o mb87078.o mermaid.o \
 			pandora.o seibusnd.o sknsspr.o slapstic.o st0020.o t5182.o timekpr.o tms34061.o v3021.o vdc.o tms9928a.o \
 			\
 			ay8910.o burn_y8950.o burn_ym2151.o burn_ym2203.o burn_ym2413.o burn_ym2608.o burn_ym2610.o burn_ym2612.o \

src/burn/devices/mb87078.cpp

@@ -0,0 +1,166 @@
+#include "burnint.h"
+#include "mb87078.h"
+
+static INT32        m_gain[4];       /* gain index 0-63,64,65 */
+static INT32        m_channel_latch; /* current channel */
+static UINT8        m_latch[2][4];   /* 6bit+3bit 4 data latches */
+static UINT8        m_reset_comp;
+static void         (*m_gain_changed_cb)(INT32, INT32) = NULL;
+
+static void reset_comp_w( int level );
+
+static const float mb87078_gain_decibel[66] = {
+	0.0, -0.5, -1.0, -1.5, -2.0, -2.5, -3.0, -3.5,
+	-4.0, -4.5, -5.0, -5.5, -6.0, -6.5, -7.0, -7.5,
+	-8.0, -8.5, -9.0, -9.5,-10.0,-10.5,-11.0,-11.5,
+	-12.0,-12.5,-13.0,-13.5,-14.0,-14.5,-15.0,-15.5,
+	-16.0,-16.5,-17.0,-17.5,-18.0,-18.5,-19.0,-19.5,
+	-20.0,-20.5,-21.0,-21.5,-22.0,-22.5,-23.0,-23.5,
+	-24.0,-24.5,-25.0,-25.5,-26.0,-26.5,-27.0,-27.5,
+	-28.0,-28.5,-29.0,-29.5,-30.0,-30.5,-31.0,-31.5,
+	-32.0, -256.0
+	};
+
+static const int mb87078_gain_percent[66] = {
+	100,94,89,84,79,74,70,66,
+	63,59,56,53,50,47,44,42,
+	39,37,35,33,31,29,28,26,
+	25,23,22,21,19,18,17,16,
+	15,14,14,13,12,11,11,10,
+	10, 9, 8, 8, 7, 7, 7, 6,
+	6, 5, 5, 5, 5, 4, 4, 4,
+	3, 3, 3, 3, 3, 2, 2, 2,
+	2, 0
+};
+
+void mb87078_init(void (*callback)(INT32, INT32))
+{
+	m_gain_changed_cb = callback;
+	mb87078_reset();
+}
+
+void mb87078_exit()
+{
+	// nothing to do here
+}
+
+void mb87078_scan()
+{
+	SCAN_VAR(m_channel_latch);
+	SCAN_VAR(m_reset_comp);
+	SCAN_VAR(m_gain);
+	SCAN_VAR(m_latch);
+}
+
+void mb87078_reset()
+{
+	m_channel_latch = 0;
+	m_reset_comp = 0;
+	m_gain[0] = m_gain[1] = m_gain[2] = m_gain[3] = 0;
+	memset(m_latch, 0, sizeof(m_latch));
+
+	/* reset chip */
+	reset_comp_w(0);
+	reset_comp_w(1);
+}
+
+/*****************************************************************************
+    IMPLEMENTATION
+*****************************************************************************/
+
+#define GAIN_MAX_INDEX 64
+#define GAIN_INFINITY_INDEX 65
+
+
+static INT32 calc_gain_index( INT32 data0, INT32 data1 )
+{
+//data 0: GD0-GD5
+//data 1: 1  2  4  8  16
+//        c1 c2 EN C0 C32
+
+	if (!(data1 & 0x04))
+	{
+		return GAIN_INFINITY_INDEX;
+	}
+	else
+	{
+		if (data1 & 0x10)
+		{
+			return GAIN_MAX_INDEX;
+		}
+		else
+		{
+			if (data1 & 0x08)
+			{
+				return 0;
+			}
+			else
+			{
+				return (data0 ^ 0x3f);
+			}
+		}
+	}
+}
+
+
+static void gain_recalc()
+{
+	for (INT32 i = 0; i < 4; i++)
+	{
+		INT32 old_index = m_gain[i];
+		m_gain[i] = calc_gain_index(m_latch[0][i], m_latch[1][i]);
+		if (old_index != m_gain[i])
+			m_gain_changed_cb(i, mb87078_gain_percent[m_gain[i]]);
+	}
+}
+
+
+void mb87078_write(INT32 dsel, INT32 data)
+{
+	if (m_reset_comp == 0)
+		return;
+
+	if (dsel == 0)  /* gd0 - gd5 */
+	{
+		m_latch[0][m_channel_latch] = data & 0x3f;
+	}
+	else        /* dcs1, dsc2, en, c0, c32, X */
+	{
+		m_channel_latch = data & 3;
+		m_latch[1][m_channel_latch] = data & 0x1f; //always zero bit 5
+	}
+	gain_recalc();
+}
+
+
+float mb87078_gain_decibel_r( INT32 channel )
+{
+	return mb87078_gain_decibel[m_gain[channel]];
+}
+
+
+INT32 mb87078_gain_percent_r( INT32 channel )
+{
+	return mb87078_gain_percent[m_gain[channel]];
+}
+
+static void reset_comp_w( INT32 level )
+{
+	m_reset_comp = level;
+
+	/*this seems to be true, according to the datasheets*/
+	if (level == 0)
+	{
+		m_latch[0][0] = 0x3f;
+		m_latch[0][1] = 0x3f;
+		m_latch[0][2] = 0x3f;
+		m_latch[0][3] = 0x3f;
+
+		m_latch[1][0] = 0x0 | 0x4;
+		m_latch[1][1] = 0x1 | 0x4;
+		m_latch[1][2] = 0x2 | 0x4;
+		m_latch[1][3] = 0x3 | 0x4;
+	}
+
+	gain_recalc();
+}

src/burn/devices/mb87078.h

@@ -0,0 +1,8 @@
+void mb87078_init(void (*callback)(INT32, INT32));
+void mb87078_exit();
+void mb87078_scan();
+void mb87078_reset();
+void mb87078_write(INT32 dsel, INT32 data);
+float mb87078_gain_decibel_r(INT32 channel);
+INT32 mb87078_gain_percent_r(INT32 channel);
+