Sound Generation Logic (SGL)
MPC5606S Microcontroller Reference Manual, Rev. 7
1114 Freescale Semiconductor
34.3.2.5 SGL_STATUS register
34.4 Functional description
The SGL can be used to produce two types of sounds as described below:
• Monophonic sound
The tone amplitude modulation is based on two different mixed signals.The first of these two
signals has a variable frequency and fixed duty cycle (signal1 in
Figure 34-8). The second signal
has a fixed frequency and a variable pulse width for generation of the amplitude (signal2 in
Figure 34-8). The duty cycle of this signal represents the amplitude of the generated sound. The
sound generator is generally a PWM that generates 2 different signals and a mixer to generate a
tone at the output as shown in signal 3 of Figure 34-8. It is passed through a first-order low-pass
filter to produce signal4 in Figure 34-8. This signal can be fed to the speaker interface.
Table 34-8. LOW_PERIOD field descriptions
Field Description
0–31
LOW_PERIOD
32-bit value loaded into bits [0:31] of the LOW_PERIOD counter. It defines the off period for
sound when operating in Periodic mode (that is, when bit 2 of MODE_SEL[SOUND_CTRL] is
0b1).
Offset 0x10 Access: User read/write
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R
SDCIF
W w1c
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 34-7. SGL_STATUS register
Table 34-9. SGL_STATUS field descriptions
Field Description
SDCIF Sound Duration Complete Interrrupt Flag bit. Reflects the status of the interrupt.
0 SDCIF cleared
1 SDCIF set event has occurred due to generation of interrupt
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