395727458ee_85| Application Note
Engineer to Engineer Note
EE-85
Technical Notes on using Analog Devices' DSP components and development tools
Phone: (800) ANALOG-D, FAX: (781) 461-3010, EMAIL: dsp.support@analog.com, FTP: ftp.analog.com, WEB: www.analog.com/dsp Copyright 1999, Analog Devices, Inc. All rights reserved. Analog Devices assumes no responsibility for customer product design or the use or application of customers' products or for any infringements of patents or rights of others which may result from Analog Devices assistance. All trademarks and logos are property of their respective holders. Information furnished by Analog Devices Applications and Development Tools Engineers is believed to be accurate and reliable, however no responsibility is assumed by Analog Devices regarding the technical accuracy of the content provided in all Analog Devices' Engineer-to-Engineer Notes.
Recommended Handling of Unused SHARC Pins
Last Modified: 09/30/96
Bits
Introduction The ADSP-2106x (SHARC) processors contain 240 pins. Several of these pins are only necessary for specific functions, such as the Serial Port Signals. If an application does not make use of a function the associated signals (pins) may still require a connection rather than be left floating (unconnected). The following application note suggests recommended methods of handling the pins associated with unused functions. The application note is broken down into sections based on the SHARCs functions. Within each section will be a list of each pin associated with the particular section, and the recommended handling of the unused pin.
DTx3-0, DRx, TCLKx, RCLKx: The serial port transmit receive data, transmit clock and receive clock lines all contain internal pull-up resistors, therefore they can be left floating if unused. TFSx, RFSx: The transmit frame sync and receive frame sync lines should be pulled or tied high if unused. Pulling or tying frame sync signals high will prevent unwanted power consumption if the serial ports are inadvertently enabled.
External Interface
ADDR31-0 , DATA47-0 : The address and data and select lines can be left floating if unused. MS 3-0 , PAGE, ADRCLK, REDY: The memory select, page, address clock and redy lines can be left floating because they are outputs. RD, WR, SW: In the unusual case no host is driving read or write and the SHARC is not bus master the read and write lines should be pulled high. If the SHARC is the bus master the read and write lines can be left floating. (The master drives the read and write lines.) (SW adheres to the same rules as RD and WR). ACK: If the acknowledge signal will not be used, leave ACK floating.
Link Ports
LxDAT3-0, LxCLK, LxACK: The link port data, clock and acknowledge lines all contain internal pull-up resistors, therefore they can be left floating if unused.
Serial Ports
395727458ee_85 Application Note analog Download PDF
Add this permalink to your bookmarks for future download of 395727458ee_85 ApplicationNote
Permalink: http://application.emcelettronica.com/analog/395727458ee_85
