EP2AGX95EF29C6N Datasheet, PDF (343/380 Pages) Altera Corporation – Device Interfaces and Integration

Chapter 9: Configuration, Design Security, and Remote System Upgrades in Arria II Devices
Dedicated Remote System Upgrade Circuitry
9–57
The application-not-factory (AnF) bit indicates whether the current configuration
loaded in the Arria II device is the factory configuration or an application
configuration. This bit is set low by the remote system upgrade circuitry when an
error condition causes a fall-back to the factory configuration. When the AnF bit is
high, the control register access is limited to read operations. When the AnF bit is low,
the register allows write operations and disables the watchdog timer.
In remote update mode, the factory configuration design sets this bit high (1'b1) when
updating the contents of the update register with the application page address and
watchdog timer settings.
Table 9–20 lists the remote system upgrade control register contents.
Table 9–20. Remote System Upgrade Control Register Contents
Control Register Bit
Remote System
Upgrade Mode
Value (1)
Definition
AnF (2)
Remote update
1'b0
Application not factory
PGM[23..0]
Remote update
24'b0×000000
AS configuration start address
(StAdd[23..0])
Wd_en
Remote update
1'b0
User watchdog timer enable bit
Wd_timer[11..0]
Remote update
12'b000000000000
User watchdog time-out value (most
significant 12 bits of 29-bit count
value: {Wd_timer[11..0],
17'b0})
Notes to Table 9–20:
(1) This is the default value of the control register bit.
(2) In remote update mode, the remote configuration block does not update the AnF bit automatically (you can update it manually).
Remote System Upgrade Status Register
The remote system upgrade status register specifies the reconfiguration trigger
condition. The various trigger and error conditions include:
■ Cyclic redundancy check (CRC) error during application configuration
■ nSTATUS assertion by an external device due to an error
■ Arria II device logic array triggered a reconfiguration cycle, possibly after
downloading a new application configuration image
■ External configuration reset (nCONFIG) assertion
■ User watchdog timer time-out
The contents of the status register are shown in Figure 9–27 and listed in Table 9–21.
The numbers in the figure show the bit positions within a 5-bit register.
Figure 9–27. Remote System Upgrade Status Register
4
3
2
1
0
Wd nCONFIG Core_nCONFIG nSTATUS CRC
July 2012 Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration