Functional Description
Table 2–4 summarizes the concurrent PS configuration modes supported
in the enhanced configuration device.
Table 2–4. Enhanced Configuration Devices in PS Mode
Mode Name
Mode (n =) (1) Used Outputs
Unused Outputs
Passive serial mode
1
2
DATA0
DATA[7..1]drive low
Multi-device passive
serial mode
DATA[1..0] DATA[7..2]drive low
Multi-device passive
serial mode
4
8
DATA[3..0] DATA[7..4]drive low
Multi-device passive
serial mode
DATA[7..0] -
Note to Table 2–4:
(1) This is the number of valid DATAoutputs for each configuration mode.
f
For configuration schematics and more information on concurrent
configuration, refer to Using Altera Enhanced Configuration Devices,
chapter 3 in volume 2 of the Configuration Handbook. or the appropriate
FPGA family chapter in the Configuration Handbook.
External Flash Interface
The enhanced configuration devices support external FPGA or processor
access to its flash memory. The unused portions of the flash memory can
be used by the external device to store code or data. This interface can also
be used in systems that implement remote configuration capabilities.
Configuration data within a particular configuration page can be
updated via the external flash interface and the system could be
reconfigured with the new FPGA image. This interface is also useful to
store Nios boot code and/or application code.
f
For more information on the Stratix remote configuration feature, refer
to the Using Remote System Configuration with Stratix & Stratix GX Devices
chapter of the Stratix Device Handbook.
The address, data, and control ports of the flash memory are internally
connected to the enhanced configuration device controller and to external
device pins. An external source can drive these external device pins to
access the flash memory when the flash interface is available.
This external flash interface is a shared bus interface with the
configuration controller chip. The configuration controller is the primary
bus master. Since there is no bus arbitration support, the external device
can only access the flash interface when the controller has tri-stated its
2–12
Altera Corporation
Configuration Handbook, Volume 2
August 2005
ALTERA [ ALTERA CORPORATION ]
