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ATSAM9753

1774D–DRMSD–11/02

automates many of the system I/O transfers to minimize the amount of overhead pro-

cessing required from the P16.

Memory Management

Unit (MMU)

The Memory Management Unit (MMU) block allows external ROM and/or RAM memory

resources to be shared between the synthesis/DSP and the P16 control processor. This

allows a single ROM device to serve as sample memory storage for the DSP and as

program storage for the P16 control processor. An internal 32K x 16 RAM is also con-

nected to the MMU, allowing RAM resources to be shared between the DSP for delay

lines and the P16 for program data.

Scanning Interface

The scanning interface consists of hardwired logic. It time-multiplexes keyboards,

switches and LED connections, thus minimizing the amount of wiring required. It com-

municates with the P16 through an 128 x 16 dual-port RAM and a few control registers.

When a new incoming event is detected, such as key-on, key-off or switch change, the

scanning interface will notify the P16 by indicating the type of event. The P16 then sim-

ply reads the dual-port RAM to get the corresponding parameter, such as velocity or

switch status. Conversely, the P16 simply writes into the dual-port RAM the LED states

to be displayed and the scanning interface will then take care of time-multiplexing the

display.

The scanning interface uses an unique key velocity detect scheme with a pseudo-loga-

rithmic time scale. This allows velocities to be accurately detected, even when keyboard

keys are pressed very softly.

Finally, a built-in 8-bit analog-to-digital converter (ADC) allows the connection of up to

16 continuous controllers through external analog multiplexers such as the 4051.

LCD Display Interface

The LCD display interface uses a dedicated bi-directional data bus (DB[7:0]), an instruc-

tion/data control (RS), a read/write signal (R/W) and an enable signal (ENB). Built-in

features are included to accommodate even the slowest LCD displays.

Flash Programming

The ATSAM9753 enables Flash memory programming in three different ways:

•

Blank Flash programming is done by the debug interface. This mode is very slow

and should be reserved for the initial boot sector programming.

•

Program update. All the Flash content can be re-programmed. The ATSAM9753

cannot play music during the Flash erase and programming. A specific firmware is

used to program Flash with the DSP.

•

Parameter update, e.g., in keyboard applications, backup parameter and sequencer

song. If the Flash enables concurrent read while program/erase, it is possible to

backup parameters in the upper memory plane while the microprocessor firmware is

running on the lower plane. The ATSAM9753 cannot play music during the

parameter backup because sound samples are stored in both memory planes.

Flash Features

•

3.3V or 5V: In case of 3.3V, the I/O voltage V

the external components (MIDI, DAC, …) should be 3.3V

•

Access time: 100 ns (for 11.2896 MHz crystal)

•

Bottom boot

•

Dual plane with concurrent read while program/erase recommended for parameters

backup