AN 981: Using Generic QSPI Flash on SDM Devices

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ID 778053
Date 7/02/2024
Public
Document Table of Contents
Document Table of Contents x
1. Introduction 2. Overview 3. Requirements 4. Implementation Flow 5. Debugging QSPI Flash Device using QSPI Debugger 6. Document Revision History for AN 981: Using Generic QSPI Flash on SDM Devices
3. Requirements x
3.1. QPI Mode (4-4-4 protocol) 3.2. Sector Erase Size 3.3. Maximum QSPI Clock 3.4. QSPI Flash Device Reset Pin 3.5. QSPI Page Program Opcode 3.6. SFDP Parameters
4. Implementation Flow x
4.1. Generating Programming Files using Programming File Generator 4.2. Programming .jic files into QSPI Flash Device 4.3. Hard Processor System (HPS) Support
1. Introduction
2. Overview
3. Requirements
4. Implementation Flow
5. Debugging QSPI Flash Device using QSPI Debugger
6. Document Revision History for AN 981: Using Generic QSPI Flash on SDM Devices

3.1. QPI Mode (4-4-4 protocol)

The QSPI flash device must support QPI mode. The SDM communicates to the QSPI flash device by sending opcode, address, and write data with all 4 data lines, and receiving read data and response from the flash device via the same four data lines.

Note that this is different from the Quad IO (QIO) mode (1-4-4 or 1-1-4 protocol). If the QSPI flash device does not support 4-4-4 protocol but 1-4-4/1-1-4 protocol only, it is not compatible with the SDM firmware.

SDM firmware determines whether the QSPI flash device supports QPI mode by interpreting the content read from the SFDP table based on the following steps.
  1. SDM firmware determines the QSPI flash supports QPI mode from the SFDP table.
  2. If QPI mode is supported, the SDM firmware sets the QSPI flash to QPI mode.
  3. SDM firmware reads the SFDP signature1 under QPI mode.
  4. If the SFDP signature matches, the SDM firmware continues the ASx4 configuration.
  5. If the QPI mode is not supported or the SFDP signature is not matched, the SDM firmware determines that the QSPI flash failed to enter QPI mode, and stops the configuration.
The following figure shows the timing diagram to read the SFDP signature from the QSPI flash device using 4-4-4 protocol.
Figure 2. Read SFDP in 4-4-4 Protocol Timing Diagram
1 The SFDP signature is the first DWORD in the SFDP header with a value of 0x50444653. The SDM firmware issues 5Ah to read the DWORD from address 0.
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