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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 337
UG585 (v1.11) September 27, 2016
Chapter 12
Quad-SPI Flash Controller
12.1 Introduction
The Quad-SPI flash controller is part of the input/output peripherals (IOP) located within the PS. It is
used to access multi-bit serial flash memory devices for high throughput and low pin count
applications.
The controller operates in one of three modes: I/O mode, linear addressing mode, and legacy SPI
mode. In I/O mode, software interacts closely with the flash device protocol. The software writes the
flash commands and data to the controller using the four TXD registers. Software reads the RXD
register that contains the data received from the flash device.
Linear addressing mode uses a subset of device operations to eliminate the software overhead that
the I/O mode requires to read the flash memory. Linear Mode engages hardware to issue commands
to the flash memory and control the flow of data from the flash memory bus to the AXI interface. The
controller responds to memory requests on the AXI interface as if the flash memory were a ROM
memory. In legacy mode, QSPI controller acts as a normal SPI controller.
The controller can interface to one or two flash devices. Two devices can be connected in parallel for
8-bit performance, or in a stacked, 4-bit arrangement to minimize pin count. The two device
combinations are shown in Figure 12-1.
12.1.1 Features
32-bit AXI interface for Linear Addressing mode transfers
32-bit APB interface for I/O mode transfers
Programmable bus protocol for flash memories from Micron and Spansion
Legacy SPI and scalable performance: 1x, 2x, 4x, 8x I/O widths
•Flexible I/O
°
Single SS 4-bit I/O flash interface mode
°
Dual SS 8-bit parallel I/O flash interface mode
°
Dual SS 4-bit stacked I/O flash interface mode
°
Single SS, legacy SPI interface
16 MB addressing per device (32 MB for two devices)