Synchronous Peripheral Interface (Spi); Terminating Unused Spi Port; Spi Interface General Routing Guidelines; Serial Peripheral Interface Signal Description - Intel EP80579 Manual

Intel
16.0

Synchronous Peripheral Interface (SPI)

The EP80579's Serial Peripheral Interface (SPI) is a 4-pin interface that provides a
potentially lower-cost alternative for system flash versus the Firmware Hub on the LPC
bus. The Serial Peripheral Interface is used to support only one SPI compatible flash
device - only one chip select is available. The SPI flash device can be up to 16 MB
(128 Mbits). The SPI interface operates at 20 MHz clock frequency. See the Intel
EP80579 Integrated Processor Product Line Datasheet for additional SPI compatibility
requirements.
Table 72.

Serial Peripheral Interface Signal Description

Group
Data
Data
Clock
Chip Select
16.1

Terminating Unused SPI Port

If the SPI port is not implemented on the system, terminate the signals as follows:
— SPI_MOSI - Leave as no connect (NC)
— SPI_MIS0 - Pull-up with a 10 K-ohm resistor
— SPI_CLK - Leave as no connect (NC)
— SPI_CS# - Leave as no connect (NC)
16.2

SPI Interface General Routing Guidelines

This section contains preliminary information and details for layout and routing
guidelines for the SPI BIOS Flash interface. Also, see the Serial Flash vendor
documentation for additional Serial Flash specific design considerations.
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Intel EP80579 Integrated Processor Product Line
Platform Design Guide
199
®
EP80579 Integrated Processor Product Line—Synchronous Peripheral Interface (SPI)
Signal Name
SPI_MOSI SPI serial output data from EP80579 to SPI flash device
SPI_MISO SPI serial input data from the SPI Flash Device to EP80579
SPI_CLK SPI Clock output from EP80579 to SPI Flash Device (20 MHz)
SPI chip select from EP80579 to SPI Flash Device
SPI_CS#
Note:
Description
If SPI interface is used, pull-up with 10 K-ohm resistor
for signal stabilty during power up.
®
May 2010
Order Number: 320068-005US