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Diffstat (limited to 'src/emu/sound/sn76496.c')
-rw-r--r--src/emu/sound/sn76496.c45
1 files changed, 22 insertions, 23 deletions
diff --git a/src/emu/sound/sn76496.c b/src/emu/sound/sn76496.c
index 3d1fe5af251..6ae1cbb37d7 100644
--- a/src/emu/sound/sn76496.c
+++ b/src/emu/sound/sn76496.c
@@ -128,14 +128,14 @@ sn76496_base_device::sn76496_base_device(const machine_config &mconfig, device_t
device_t *owner, UINT32 clock)
: device_t(mconfig, type, name, tag, owner, clock),
- device_sound_interface(mconfig, *this),
- m_feedback_mask(feedbackmask),
- m_whitenoise_tap1(noisetap1),
- m_whitenoise_tap2(noisetap2),
- m_negate(negate),
- m_stereo(stereo),
- m_clock_divider(clockdivider),
- m_freq0_is_max(freq0)
+ device_sound_interface(mconfig, *this),
+ m_feedback_mask(feedbackmask),
+ m_whitenoise_tap1(noisetap1),
+ m_whitenoise_tap2(noisetap2),
+ m_negate(negate),
+ m_stereo(stereo),
+ m_clock_divider(clockdivider),
+ m_freq0_is_max(freq0)
{
}
@@ -157,7 +157,7 @@ void sn76496_base_device::device_start()
for (i = 0; i < 8; i+=2)
{
m_register[i] = 0;
- m_register[i + 1] = 0x0f; // volume = 0
+ m_register[i + 1] = 0x0f; // volume = 0
}
for (i = 0; i < 4; i++)
@@ -170,8 +170,8 @@ void sn76496_base_device::device_start()
m_RNG = m_feedback_mask;
m_output[3] = m_RNG & 1;
- m_cycles_to_ready = 1; // assume ready is not active immediately on init. is this correct?
- m_stereo_mask = 0xFF; // all channels enabled
+ m_cycles_to_ready = 1; // assume ready is not active immediately on init. is this correct?
+ m_stereo_mask = 0xFF; // all channels enabled
m_current_clock = m_clock_divider-1;
// set gain
@@ -182,7 +182,7 @@ void sn76496_base_device::device_start()
// increase max output basing on gain (0.2 dB per step)
out = MAX_OUTPUT / 4; // four channels, each gets 1/4 of the total range
while (gain-- > 0)
- out *= 1.023292992; // = (10 ^ (0.2/20))
+ out *= 1.023292992; // = (10 ^ (0.2/20))
// build volume table (2dB per step)
for (i = 0; i < 15; i++)
@@ -191,7 +191,7 @@ void sn76496_base_device::device_start()
if (out > MAX_OUTPUT / 4) m_vol_table[i] = MAX_OUTPUT / 4;
else m_vol_table[i] = out;
- out /= 1.258925412; /* = 10 ^ (2/20) = 2dB */
+ out /= 1.258925412; /* = 10 ^ (2/20) = 2dB */
}
m_vol_table[15] = 0;
@@ -246,9 +246,9 @@ void sn76496_base_device::write(UINT8 data)
c = r >> 1;
switch (r)
{
- case 0: // tone 0: frequency
- case 2: // tone 1: frequency
- case 4: // tone 2: frequency
+ case 0: // tone 0: frequency
+ case 2: // tone 1: frequency
+ case 4: // tone 2: frequency
if ((data & 0x80) == 0) m_register[r] = (m_register[r] & 0x0f) | ((data & 0x3f) << 4);
if ((m_register[r] != 0) || (!m_freq0_is_max)) m_period[c] = m_register[r];
else m_period[c] = 0x400;
@@ -256,17 +256,17 @@ void sn76496_base_device::write(UINT8 data)
if (r == 4)
{
// update noise shift frequency
- if ((m_register[6] & 0x03) == 0x03) m_period[3] = m_period[2]<<1;
+ if ((m_register[6] & 0x03) == 0x03) m_period[3] = m_period[2]<<1;
}
break;
- case 1: // tone 0: volume
- case 3: // tone 1: volume
- case 5: // tone 2: volume
- case 7: // noise: volume
+ case 1: // tone 0: volume
+ case 3: // tone 1: volume
+ case 5: // tone 2: volume
+ case 7: // noise: volume
m_volume[c] = m_vol_table[data & 0x0f];
if ((data & 0x80) == 0) m_register[r] = (m_register[r] & 0x3f0) | (data & 0x0f);
break;
- case 6: // noise: frequency, mode
+ case 6: // noise: frequency, mode
{
if ((data & 0x80) == 0) logerror("sn76496_base_device: write to reg 6 with bit 7 clear; data was %03x, new write is %02x! report this to LN!\n", m_register[6], data);
if ((data & 0x80) == 0) m_register[r] = (m_register[r] & 0x3f0) | (data & 0x0f);
@@ -419,4 +419,3 @@ const device_type SN94624 = &device_creator<sn94624_device>;
const device_type NCR7496 = &device_creator<ncr7496_device>;
const device_type GAMEGEAR = &device_creator<gamegear_device>;
const device_type SEGAPSG = &device_creator<segapsg_device>;
-