AT89C51SND2C-7FTUL Atmel, AT89C51SND2C-7FTUL Datasheet - Page 63

• Manufacturer Part Number: AT89C51SND2C-7FTUL
• Description: IC 8051 MCU FLASH 64K MP3 100BGA
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51SND2C-7FTUL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, IDE/ATAPI, MMC, SPI, UART/USART, USB
• Peripherals: Audio, I²S, MP3, PCM, POR, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.3 V
• Data Converters: A/D 2x10b; D/A 2x20b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TFBGA
• Data Bus Width: 8 bit
• Data Ram Size: 2.25 KB
• Interface Type: ATAPI, I2S, IDE, SPI, UART, USB
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: AT89C51SND2C7FTUL

13. MP3 Decoder
13.1
13.1.1
Figure 13-1. MP3 Decoder Block Diagram
4341H–MP3–10/07
Decoder
CLOCK
Audio Data
From C51
MP3
Description
MP3CON.7
MPEN
8
The AT8xC51SND2C implement a MPEG I/II audio layer 3 decoder better known as MP3
decoder.
In MPEG I (ISO 11172-3) three layers of compression have been standardized supporting three
sampling frequencies: 48, 44.1, and 32 kHz. Among these layers, layer 3 allows highest com-
pression rate of about 12:1 while still maintaining CD audio quality. For example, 3 minutes of
CD audio (16-bit PCM, 44.1 kHz) data, which needs about 32M bytes of storage, can be
encoded into only 2.7M bytes of MPEG I audio layer 3 data.
In MPEG II (ISO 13818-3), three additional sampling frequencies: 24, 22.05, and 16 kHz are
supported for low bit rates applications.
The AT8xC51SND2C can decode in real-time the MPEG I audio layer 3 encoded data into a
PCM audio data, and also supports MPEG II audio layer 3 additional frequencies.
Additional features are supported by the AT8xC51SND2C MP3 decoder such as volume control,
bass, medium, and treble controls, bass boost effect and ancillary data extraction.
The C51 core interfaces to the MP3 decoder through nine special function registers: MP3CON,
the MP3 Control register (see Table 13-5); MP3STA, the MP3 Status register (see Table 13-6);
MP3DAT, the MP3 Data register (see Table 13-7); MP3ANC, the Ancillary Data register (see
Table 13-9); MP3VOL and MP3VOR, the MP3 Volume Left and Right Control registers (see
Table 13-10 and Table 13-11); MP3BAS, MP3MED, and MP3TRE, the MP3 Bass, Medium, and
Treble Control registers (see Table 13-12, Table 13-13, and Table 13-14); and MPCLK, the MP3
Clock Divider register (see Table 13-15).
Figure 13-1 shows the MP3 decoder block diagram.
MPBBST
MP3CON.6
Frame Buffer
MPxREQ
MP3STA1.n
1K Bytes
MP3DAT
Anti-Aliasing
MP3VOL
MP3STA.5:3
ERRxxx
MP3VOR
Huffman Decoder
Header Checker
MP3STA.2:1
MPFS1:0
IMDCT
MP3BAS
MP3STA.0
MPVER
MP3MED
Sub-band
Synthesis
AT8xC51SND2C/MP3B
Dequantizer
Ancillary Buffer
MP3TRE
MP3ANC
Side Information
16
Stereo Processor
Decoded Data
To Audio Interface
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