Intel® Quartus® Prime Standard Edition User Guide: Partial Reconfiguration

ID 683499
Date 9/24/2018
Public
Document Table of Contents

1.12.4. Implementing Memories with Initialized Content

If your Stratix V PR design implements ROMs, RAMs with initialization, or ROMs within the PR regions, using either M20K blocks or LUT-RAMs, then you must follow the following design guidelines to determine what is applicable in your case.

Table 7.  Implementing Memory with Initialized Content in PR Designs

Mode

Production Devices

AND/OR

SCRUB

LUT-RAM without initialization

Suggested Method

While design is running: Write ‘1’ to all locations before partial reconfiguration.

At compile time: Explicitly initialize all memory locations in each new persona to ‘1’ via initialization file (.mif)

Make sure no spurious write on PR entry 1

No special method required

Without Suggested Method

CRC Error No special method required

LUT-RAM with initialization

Suggested Method

Not supported

Make sure no spurious write on PR exit 1

Without Suggested Method

Incorrect results

M20K without initialization

Suggested Method

No special method required

Without Suggested Method

No special method required

M20K with initialization

Suggested Method

Use double PR cycle 2

Make sure no spurious write on PR exit 1

No special method required

Without Suggested Method

Incorrect results No special method required
Figure 24. M20K/LUTRAMTo avoid spurious writes during PR entry and exit, implement the following clock enable circuit in the same PR region as the RAM.

The circuit depends on an active- high clear signal from the static region. Before entering PR, freeze this signal in the same manner as all PR inputs. Your host control logic should de-assert the clear signal as the final step in the PR process.

1 Use the circuit shown in the M20K/LUTRAM figure to create clock enable logic to safely exit partial reconfiguration without spurious writes.
2 Double partial reconfiguration is described in Initializing M20K Blocks with a Double PR Cycle