CD00237391 Datasheet, PDF (161/177 Pages) STMicroelectronics – ARM-based 32-bit MCU, 150DMIPs, up to 1 MB Flash/128+4KB RAM

STM32F20xxx
Application block diagrams
A.5
Complete audio player solutions
Two solutions are offered, illustrated in Figure 90 and Figure 91.
Figure 90 shows storage media to audio DAC/amplifier streaming using a software Codec.
This solution implements an audio crystal to provide audio class I²S accuracy on the master
clock (0.5% error maximum, see the Serial peripheral interface section in the reference
manual for details).
Figure 90. Complete audio player solution 1
XTAL
25 MHz
or 14.7456 MHz
USB
Mass-storage
device
MMC/
SDCard
Cortex-M3 core
up to 120 MHz
Program memory
OTG
(host
mode) +
PHY
SPI/
FSMC
File
System
Audio
CODEC
User
application
SPI
GPIO
I2S
LCD
touch
screen
Control
buttons
DAC +
Audio
ampli
Figure 91 shows storage media to audio Codec/amplifier streaming with SOF
synchronization of input/output audio streaming using a hardware Codec.
ai16039c
Figure 91. Complete audio player solution 2
XTAL
25 MHz
or 14.7456 MHz
USB
Mass-storage
device
SOF
MMC/
SDCard
Cortex-M3 core
up to 120 MHz
SPI/
FSMC
OTG
+
PHY
Program memory
File
System
GPIO
I2S
SPI/
FSMC
User
application
SOF synchronization of input/output
audio streaming
1. SOF = start of frame.
LCD
touch
screen
Control
buttons
Audio PLL
+DAC
Audio
ampli
ai16040c
Doc ID 15818 Rev 9
161/177