CS4953xx Data Sheet

32-bit Audio Decoder DSP Family

DS705PP6

Copyright 2009 Cirrus Logic

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4.3.2 Termination Requirements

Open-drain pins on the CS4953xx must be pulled high for proper operation. Please refer to the CS4953xx

Hardware User’s Manual to identify which pins are open-drain and what value of pull-up resistor is required for

proper operation.

Mode select pins on the CS4953xx are used to select the boot mode upon the rising edge of reset. A detailed

explanation of termination requirements for each communication mode select pin can be found in the

CS4953xx Hardware User’s Manual.

4.3.3 Pads

The CS4953xx I/O operates from the 3.3 V supply and is 5V tolerant.

4.4 Application Code Security

The external program code may be encrypted by the programmer to protect any intellectual property it may

contain. A secret, customer-specific key is used to encrypt the program code that is to be stored external to the

device.