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12–8
Altera Corporation
Stratix Device Handbook, Volume 2
September 2004
Remote Configuration Operation
Remote Update Sub-Block
The remote update sub-block is responsible for administrating the remote
configuration feature. This sub-block, which is controlled by a remote
configuration state machine, generates the control signals required to
control different remote configuration registers.
Remote Configuration Registers
Remote configuration registers are a series of registers required to keep
track of page addresses and the cause of configuration errors.
Table 12–2gives descriptions of the registers’ functions. You can control both the
update and shift registers; the status and control registers are controlled
by internal logic, but can be read via the shift register.
Figure 12–6 shows the control, update, shift, and status registers and the
data path used to control remote system configuration.
Table 12–2. Remote Configuration Registers
Register
Description
Control register
This register contains the current page address, the watchdog timer setting, and
one bit specifying if the current configuration is a factory or application
configuration. During a capture in an application configuration, this register is
read into the shift register.
Update register
This register contains the same data as the control register, except that it is
updated by the factory configuration. The factory configuration updates the
register with the values to be used in the control register on the next re-
configuration. During capture in a factory configuration, this register is read into
the shift register.
Shift register
This register is accessible by the core logic and allows the update, status, and
control registers to be written and sampled by the user logic. The update register
can only be updated by the factory configuration in remote configuration mode.
Status register
This register is written into by the remote configuration block on every re-
configuration to record the cause of the re-configuration. This information is used
by factory configuration to determine the appropriate action following a re-
configuration.