16 16-BIT AUDIO PWM TIMER (T16P)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
16-1
16-bit Audio PWM Timer (T16P)
16
T16P Module Overview
16.1
The S1C33L26 incorporate a 16-bit audio PWM timer (T16P) that generates PWM pulses from PCM data. The
pulses generated can be directly output to a low pass filter that eliminates quantization noise to shape the output
signal into sound waveform. A monophonic audio output system can be implemented simply without an external D/
A converter.
16-bit audio PWM timer (T16P)
PCM data
LPF
AMP
PWM waveform
S1C33L26
Sound waveform
1.1 Audio Output Circuit Using T16P
Figure 16.
If no audio output feature is required, T16P can be used as a general-purpose 16-bit timer.
The following lists the main functions of T16P.
• Supports 8-bit and 16-bit PCM data with varied sample rates: 8, 16, 22.05, 32, 44.1, and 48 kHz.
• Supports both signed and unsigned PCM data.
• Supports split mode; 16-bit audio data can be split into 10 bits + 6 bits, 9 bits + 7 bits, or 8 bits + 8 bits.
• Supports fine mode to improve the precision of the pulse width.
• Includes a digital volume control unit.
• Programmable count clocks using the prescaler or an external clock
• Built-in two 16-bit data buffers for setting pulse widths (duty cycles) and pulse periods
• Can generate three different types of interrupts and invoke a DMA.
Figure 16.1.2 shows the T16P configuration.
16-bit up counter
Compare A register
Compare B register
Volume control unit
Control circuit
Clock control
circuit
Prescaler
Comparator
PWM_H
PWM_L
Clock output
To ITC
B match
A match
AH/AL
match
Interrupt
16-bit Audio PWM Timer (T16P)
PWM_EXCL
Internal data bus
Compare A buffer
Comparator
1.2 16-bit Audio PWM Timer (T16P) Configuration
Figure 16.