This document is a user guide for the Dynamic Calibrated On-Chip Termination (ALTOCT) Megafunction by Altera Corporation. The product features dynamic calibrated on-chip termination.
This February 2012 Altera user guide describes the Dynamic Calibrated On-Chip Termination (ALTOCT) megafunction, which is used in DDR external memory interfaces and is closely associated with the ALTMEMPHY megafunction. It covers features and device support, MegaWizard and command-line parameter settings, OCT architecture, power-up and on-demand calibration in Quartus II software, a design example, and ALTOCT ports.
The megafunction supports up to 10 OCT blocks, calibrated on-chip series (RS) and parallel (RT) termination on all I/O pins, and termination values of 25 and 50 ohm. The guide lists support for Arria II GX, Arria II GZ, Arria V, Cyclone V, HardCopy III, HardCopy IV, Stratix III, Stratix IV, and Stratix V devices.
| OCT blocks supported | Up to 10 |
|---|---|
| Calibrated termination values | 25 and 50 ohm |
| Calibration code width | 14-bit RS code and 14-bit RT code (28-bit total) |
| Shift-out clock cycles | 28 clock cycles using OCTUSRCLK |
| OCT block number range | 1 to 10 |
It is used in double-data rate (DDR) external memory interfaces and is closely associated with the ALTMEMPHY megafunction.
It supports up to 10 OCT blocks.
The supported calibrated termination values are 25 and 50 ohm.
It can be parameterized with the MegaWizard Plug-In Manager or the command-line interface (CLI).