Atmel AT83SND2C MP3 - Manual (Page 10)

Functional Description
2-6 AT83SND2CMP3 User Guide
7525A–MP3–07/05
2.2.1 USB AT83SND2CMP3 USB interface complies to the USB 2.0 Full Speed specifications.
The USB bus is used to download music using bulk transfer.
The system supports Mass Storage on the following platforms: Win98 with Atmel driver,
Win2000/ME/XP. These platforms do not provide multi-drive (multiple USB Logical Unit)
support, except Win2000 Service Pack 3 that allows multi-drive support.
2.2.2 SD/MMC Card Memory cards are controlled by AT83SND2CMP3 and can be considered as removable
disk drives: copying from any PC storage media to the memories is then possible.
Note: Only SD Card and MMC cards with block size of 512 bytes and compliant with Secure
Digital Card Specification and MultiMediaCard System Specification Version 3.1 are
accepted. SD card is used in 1-bit mode (like MMC card). 4-bit mode is not supported.
2.2.3 Audio Output „ Stereo Headset (32 Ohm)
„ Loud Speaker (8 Ohm)
2.2.4 Audio Input An external mono audio input signal and an external stereo audio input can be
connected to AT83SND2CMP3. Refer to AT83SND2CMP3 datasheet to connect audio
mono auxiliary positive and negative input (AUXP and AUXN), and stereo Line-in input
(LINEINL, LINEINR). Audio input are not disable during USB mass storage.
2.2.5 UART Link The physical link between Remote Controller and AT8xC51SND2C is UART plus one or
more signals for data link handshaking when needed. The default baudrate is 115200
bps (physical baudrate is 111 111 bps) and can be changed later with a special
command.
2.2.6 Power Management To prevent system malfunctions during periods of insufficient power supply voltage,
AT83SND2CMP3 voltage supply shall be monitored by a voltage supervisor.
Note: Refer to Atmel Document ‘External Brown-out Protection for C51 Microcontrollers with
Active High Reset Input’.
„ Power supply requested in Player mode: 2.7V – 3.6V
„ Power supply requested in USB mode: 3.0V – 3.6V
„ Audio Power Amplifier voltage AUDVBAT for loud speaker shall be from 3.2V to
5.5V. Refer to AT83SND2CMP3 datasheet for specification.
The communication protocol provides POWERDOWN and WAKEUP commands to
optimize the system power consumption.
2.2.7 Clock AT83SND2CMP3 Frequency oscillator value: 16 MHz.