Owner's manual

Features
The features supported by the embedded DDR controllers are highlighted below:
1866 Mbps data rate
The controller and PHY can run at 1066 MHz to achieve 1866 Mbps rate at the
memory interface. A 2X Clock setting enables the core to run at half the speed -
533MHz. There is an additional feature to enable a wide bus interface, which
effectively enables the core to run at one quarter the speed - 266MHz. The 2X
clock setting and wide bus interfaces can be enabled at any data rate, thereby
reducing the core frequency by half, or a quarter, respectively.
4 Chip Selects per controller
The external memory connected to each controller can comprise of up to 4 ranks
(either two dual-rank DIMMs or one quad rank DIMM)
Registered DIMM and Unbuffered DIMM support
Each controller can independently support either rDIMMs or uDIMMs
Address mirroring is supported.
Multi-Burst Mode
Each controller supports multi-burst mode, up to a burst length of 252 (DDR2) /
254 (DDR) / 248(DDR3). This allows the embedded controller to automatically
issue up to 252 cascaded read or write commands to automatically increment
addresses based on a single command from the Core Fabric
Backwards Compatible
The embedded DDR controllers can support DDR3 (up to 1866 Mbps), DDR2 (up
to 800 Mbps) and DDR protocols
Bypassable
If the user does not require all six DDR controllers, any (or all) can be bypassed
to leverage use of the designated I/Os for other purposes
If the user does not require all 72-bits of the data bus, unused byte lanes can be
bypassed to leverage use of the designated I/Os for other purposes
Minimal LUT use
The DDR controllers are embedded (hardened), and therefore do not use any of
the LUTs in the core fabric
LUTs are only required to interface the DDR Controllers
Zero License fees
6 UG031, Nov 18, 2014