atsam3303b ATMEL Corporation, atsam3303b Datasheet - Page 3

• Manufacturer Part Number: atsam3303b
• Description: Atsam3303b Audio Processing
• Manufacturer: ATMEL Corporation

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6091D–DRMSD–12-Feb-07
Sync Bus
Async Bus
16-bit Processor
MMU (Memory Management Unit)
Router: Final ACC, MIX, Audio Out, Audio In
I/O
The Sync Bus transfers data on a frame basis, typical frame rates being 32, 44.1, 48 or 96 kHz.
Each frame is divided into 64 time slots. Each slot is divided into 4 bus cycles. Each P24 is
assigned a hardwired time slot (8 to 63), during which it may provide 24-bit data to the bus (up to
4 data samples). Each P24 can read data on the bus at any time, allowing inter P24 communica-
tion at the current sampling rate. Slots 0 to 7 are reserved for a specific router DSP, which also
handles audio out, audio in, and remix send.
The Async Bus is 24-bit data inside the chip and 16-bit outside.
The P16 processor normally masters the Async Bus; it can read/write the P24 memories and the
external or embedded ROM/RAM. However, each P24 can request a bus master cycle for
accessing external ROM/RAM or other P24 memories. This allows efficient intercommunication
between several P24s on asynchronous block basis. Specific P24 instructions FLOAT and FIX
convert fixed-point DSP data to floating-point 16 bits. This allows for 20-bit audio dynamic range
when using 16-bit external memory.
The P16 processor is widely used in ATSAM products. Using the P16 allows to keep the large
firmware investments from the ATSAM97xx series. A built-in ROM, connected to the P16, holds
basic input/output software (BIOS) for peripherals such as UART, DataFlash
MPU, as well as a debugger using a dedicated asynchronous serial line. The firmware can
reside on external parallel ROM/Flash or it can be downloaded at power-up into the built-in 16K
x 24 RAM from serial EEPROM, DataFlash, SmartMedia or host.
The MMU handles transfer requests between the external or embedded RAM/ROM, the P16
and the P24s through the Async Bus. The ATSAM3303B includes an on-chip 16K x 24 RAM.
This block includes a RAM, accessed through the Async Bus, which defines the routing from the
Sync Bus to/from the Audio I/O or back to the Sync Bus (mix send). It takes care of mix and
accumulation from Sync Bus samples. Eight channels of audio in and eight channels of audio
out are provided (4 stereo in/out, I2S format). The stereo audio in channels may have a different
sampling rate than the audio out channels. In this case, one or more P24s take care of sampling
rate conversion.
The ATSAM3303B includes versatile I/Os that share common pins for reduced pin count and
small IC footprint. Most I/Os, when not used for a specific function, remain available as firmware
controlled general-purpose pins.
The following peripherals are included on-chip:
• 2 x 8-bit timers
• 2 x 16-bit timers
• Parallel slave 8-bit port, MPU401 compatible
• Parallel master 8-bit port, for connection to SmartMedia and/or LCD display, switches, etc.
ATSAM3303B
®
, SmartMedia
™
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