Functional Description Of The Quad Spi Flash Controller; Overview; Data Slave Interface; Register Slave Interface - Altera Cyclone V Device Handbook

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2013.12.30

Functional Description of the Quad SPI Flash Controller

Overview

Note: Terms used in this section are defined in detail in the sections that follow.
The quad SPI flash controller uses the register slave interface to select the operation modes and configure
the data slave interface for data transfers. The quad SPI flash controller uses the data slave interface for direct
and indirect accesses, and the register slave interface for software triggered instruction generator (STIG)
operation and SPI legacy mode accesses.
Accesses to the data slave are forwarded to the direct or indirect access controller. If the access address is
within the configured indirect address range, the access is sent to the indirect access controller.

Data Slave Interface

The quad SPI flash controller uses the data slave interface for direct, indirect, and SPI legacy mode accesses.
For information about these modes, refer to the following sections.
The data slave is 32 bits wide. Byte, half-word, and word accesses are permitted.
For write accesses, only incrementing bursts are supported, and only of sizes 1, 4, 8, and 16 transfers. For
read accesses, all burst types and sizes are supported.

Register Slave Interface

The quad SPI flash controller uses the register slave interface to configure the quad SPI controller through
the quad SPI configuration registers, and to access flash memory under software control, through the
flashcmd register in the STIG.

Direct Access Mode

In direct access mode, an access to the data slave triggers a read or write command to the flash memory. To
use the direct access mode, enable the direct access controller with the enable direct access controller bit
(endiracc) of the quad SPI configuration register (cfg).
An external master, for example a processor, triggers the direct access controller with a read or write operation
to the data slave interface. The data slave exposes a 1 MB window into the flash device. You can remap this
window to any 1 MB location within the flash device.
Quad SPI Flash Controller
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Functional Description of the Quad SPI Flash Controller
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