summaryrefslogtreecommitdiffstatshomepage
path: root/src/devices/sound/mm5837.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/devices/sound/mm5837.h')
-rw-r--r--src/devices/sound/mm5837.h42
1 files changed, 21 insertions, 21 deletions
diff --git a/src/devices/sound/mm5837.h b/src/devices/sound/mm5837.h
index abe1a2a2ec2..49374537b9c 100644
--- a/src/devices/sound/mm5837.h
+++ b/src/devices/sound/mm5837.h
@@ -128,22 +128,22 @@ public:
static u32 frequency(double vdd)
{
// Vdd should be negative -6.2..-15V
- if (vdd > -6.2 || vdd < -15)
- throw emu_fatalerror("mm5837 frequency should be -6.2V .. -15V");
-
- // curve fitting done in excel from this table:
- // { 0, 0, 0, 0, 0, 0, 1, 2267, 8731, 16382, 23531, 32564, 38347, 40010, 37800, 33173 }
- double result = 191.98*vdd*vdd*vdd + 5448.4*vdd*vdd + 43388*vdd + 105347;
-
- // datasheet claims frequency range 24-56kHz at Vdd=-14V, but also lists
- // maximum cycle times as ranging from 1.1-2.4s; since the 17-bit shift
- // register cycles after 131072 clocks, we would expect the actual cycle
- // times to be 2.34-5.46s at the 24-56kHz frequency range, so I'm presuming
- // that it ticks 2x per "clock", effectively running at 2x the frequency
- result *= 2;
-
- // make sure the result isn't TOO crazy
- result = std::max(result, 100.0);
+ if (vdd > -6.2 || vdd < -15)
+ throw emu_fatalerror("mm5837 frequency should be -6.2V .. -15V");
+
+ // curve fitting done in excel from this table:
+ // { 0, 0, 0, 0, 0, 0, 1, 2267, 8731, 16382, 23531, 32564, 38347, 40010, 37800, 33173 }
+ double result = 191.98*vdd*vdd*vdd + 5448.4*vdd*vdd + 43388*vdd + 105347;
+
+ // datasheet claims frequency range 24-56kHz at Vdd=-14V, but also lists
+ // maximum cycle times as ranging from 1.1-2.4s; since the 17-bit shift
+ // register cycles after 131072 clocks, we would expect the actual cycle
+ // times to be 2.34-5.46s at the 24-56kHz frequency range, so I'm presuming
+ // that it ticks 2x per "clock", effectively running at 2x the frequency
+ result *= 2;
+
+ // make sure the result isn't TOO crazy
+ result = std::max(result, 100.0);
return u32(result);
}
@@ -171,10 +171,10 @@ protected:
virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
private:
- // internal state
+ // internal state
devcb_write_line m_output_cb; // output callback
- emu_timer *m_timer; // output timer
- double m_vdd; // configured voltage
+ emu_timer *m_timer; // output timer
+ double m_vdd; // configured voltage
mm5837_source m_source; // noise source
};
@@ -199,8 +199,8 @@ protected:
private:
sound_stream *m_stream; // sound stream
- double m_vdd; // configured voltage
- mm5837_source m_source; // noise source
+ double m_vdd; // configured voltage
+ mm5837_source m_source; // noise source
};