
Altera Corporation
14–15
October 2007
Stratix II GX Device Handbook, Volume 2
Remote System Upgrades with Stratix II & Stratix II GX Devices
Figure 14–6. Remote System Upgrade Circuit Data Path
Remote System Upgrade Registers
The remote system upgrade block contains a series of registers that store
the page addresses, watchdog timer settings, and status information.
Logic Array
Shift Register
Status Register (SR)
Bit [4..0]
Control Register
Bit [20..0]
din
capture
dout
Bit [4..0]
Logic
clkout
RU_SHIFTnLD
RU_CAPTnUPDT
RU_CLK
RU_DIN
RU_nCONFIG
RU_nRSTIMER
User
Watchdog
Timer
RU_DOUT
capture
clkin
update
Logic
capture
din
Bit [20..0]
dout
update
Update Register
Bit [20..0]
timeout
RSU
State
Machine
Internal Oscillator
Table 14–3. Remote System Upgrade Registers (Part 1 of 2)
Register
Description
Shift register
This register is accessible by the logic array and allows the update, status, and control
registers to be written and sampled by user logic. Write access is enabled in remote update
mode for factory configurations to allow writes to the update register. Write access is
disabled in local update mode and for all application configurations in remote update mode.
Control register
This register contains the current page address, the user watchdog timer settings, and one
bit specifying whether the current configuration is a factory configuration or an application
configuration. During a read operation in an application configuration, this register is read
into the shift register. When a reconfiguration cycle is initiated, the contents of the update
register are written into the control register.