EP3C10U256C6N Datasheet, PDF (222/274 Pages) Altera Corporation – Cyclone III Device Family Overview

9–64
Chapter 9: Configuration, Design Security, and Remote System Upgrades in the Cyclone III Device Family
Configuration Features
ACTIVE_ENGAGE
The ACTIVE_ENGAGE instruction allows you to re-engage a disengaged active controller.
You can issue this instruction any time during configuration or user mode to re-
engage an already disengaged active controller as well as trigger reconfiguration of
the Cyclone III device family in the active configuration scheme specified by the
MSEL pin settings.
The ACTIVE_ENGAGE instruction functions as the PULSE_NCONFIG instruction when the
device is in passive configuration schemes (PS or FPP). The nCONFIG pin is disabled
when the ACTIVE_ENGAGE instruction is issued.
1 Altera does not recommend using the ACTIVE_ENGAGE instruction but it is provided as
a fail-safe instruction for re-engaging the active configuration (AS or AP) controllers.
Changing the Start Boot Address of the AP Flash
In the AP configuration scheme, for Cyclone III devices only, you can change the
default configuration boot address of the parallel flash memory to any desired
address using the APFC_BOOT_ADDR JTAG instruction.
APFC_BOOT_ADDR
The APFC_BOOT_ADDR instruction is for Cyclone III devices only and allows you to
define a start boot address for the parallel flash memory in the AP configuration
scheme.
This instruction shifts in a start boot address for the AP flash. When this instruction
becomes the active instruction, the TDI and TDO pins are connected through a 22-bit
active boot address shift register. The shifted-in boot address bits get loaded into the
22-bit AP boot address update register, which feeds into the AP controller. The content
of the AP boot address update register can be captured and shifted-out of the active
boot address shift register from TDO.
The boot address in the boot address shift register and update register are shifted to
the right (in the LSB direction) by two bits versus the intended boot address. The
reason for this is that the two LSB of the address are not accessible. When this boot
address is fed into the AP controller, two 0s are attached in the end as LSB, thereby
pushing the shifted-in boot address to the left by two bits, which become the actual
AP boot address the AP controller gets.
If you have enabled the remote update feature, the APFC_BOOT_ADDR instruction sets
the boot address for the factory configuration only.
1 The APFC_BOOT_ADDR instruction is retained after reconfiguration while the system
board is still powered on. However, you must reprogram the instruction whenever
you restart the system board.
Device Configuration Pins
Table 9–21 through Table 9–23 describe the connections and functionality of all the
configuration-related pins on Cyclone III device family.
Cyclone III Device Handbook
Volume 1
August 2012 Altera Corporation