CDPCLK4 datasheet(237/274 Pages) ALTERA

237 / 274 page

Chapter 9: Configuration, Design Security, and Remote System Upgrades in the Cyclone III Device Family

9–79

Remote System Upgrade

August 2012

Altera Corporation

Cyclone III Device Handbook

Volume 1

The following actions cause the remote system upgrade status register to be written:

■ nSTATUS

driven low externally

■

Internal CRC error

■

User watchdog timer time-out

■

A configuration reset (logic array nCONFIG signal or external nCONFIG pin assertion)

Cyclone III device family automatically load the factory configuration located at

address boot_address[23:0] = 24'b0 for the AS configuration scheme, and default

address boot_address[23:0] = 24'h010000 (or the updated address if the default

address is changed) for the AP configuration scheme. This user-designed factory

configuration reads the remote system upgrade status register to determine the reason

for reconfiguration. Then the factory configuration takes the appropriate error

recovery steps and writes to the remote system upgrade control register to determine

the next application configuration to be loaded.

When Cyclone III device family successfully load the application configuration, the

devices enter user mode. In user mode, the soft logic (Nios II processor or state

machine and the remote communication interface) assists the Cyclone III device

family in determining when a remote system update is arriving. When a remote

system update arrives, the soft logic receives the incoming data, writes it to the

configuration memory device, and triggers the device to load the factory

configuration. The factory configuration reads the remote system upgrade status

system upgrade control register accordingly, and starts system reconfiguration.

CDPCLK4 Scheda tecnica(PDF) 237 Page - Altera Corporation