Cirrus Logic CS49DV8C - Manual (Page 9)

DS868PP2 Copyright 2008 Cirrus Logic, Inc. 9
CS49DV8C Data Sheet
32-bit Audio DSP Family
4.3 DSP I/O Description
4.3.1 Multiplexed Pins
Many of the CS49DV8C pins are multi-functional. For details on pin functionality please refer to the
CS4953xx Hardware User’s Manual.
4.3.2 Termination Requirements
Open-drain pins on the CS49DV8C 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 CS49DV8C 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 CS49DV8C I/O operates from the 3.3 V supply and is 5 V 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.