Quad SPI Boot Mode

Versal ACAP Technical Reference Manual (AM011)

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1.4 English

The Versal ACAP supports a 24-bit addressing mode (QSPI24) boot mode or a 32-bit addressing (QSPI32) boot mode option. The QSPI32 boot mode option addresses flash sizes greater than 128 Mb. The QSPI boot mode supports multiple data bus widths and setups. In the QSPI boot modes, the BootROM runs at a QSPI device clock frequency between 11 MHz and 24.5 MHz dependent on the REF_CLK setting. For additional information on the quad SPI controller, see Quad SPI Controller. For details on QSPI flash support, see the Vivado Design Suite User Guide: Programming and Debugging (UG908).

The QSPI boot mode setups supported are listed in the following table.

Table 1. Quad SPI Boot Mode Setups
Quad SPI Setup Flash Device Count Chip Select Count Data Width Max
Single (1-bit, 2-bit, 4-bit) 1 1 4
Dual-stacked 1 (1-bit, 2-bit, 4-bit) 2 2 4
Dual-parallel (8-bit) 2 2 8
  1. When using QSPI dual-stacked mode, the BootROM can only access the lower QSPI addressable flash memory space for boot. After boot, the PLM can access the upper QSPI for additional image storage.

The boot mode image search limits are listed in Table 3.

QSPI devices support different commands. The RCU supports a common subset of commands for boot as listed in the following table.

Table 2. Quad SPI Commands Supported by the RCU
Boot Mode Data Width Read Mode Command Code Dummy Cycles
QSPI24 1 Normal read (3-Byte) 03h -
QSPI24 2 Dual Output fast read (3-Byte) 3Bh 8
QSPI24 4 Quad Output fast read (3-Byte) 6Bh 8
QSPI32 1 Normal read (4-Byte) 13h -
QSPI32 2 Dual Output fast read (4-Byte) 3Ch 8
QSPI32 4 Quad Output fast read (4-Byte) 6Ch 8
QSPI32 8 Quad Output fast read (4-Byte) 6Ch 8