Qspi Flash; Qspi Flash Type; Signal Description; Qspi Flash Corruption Risk - Enclustra Mercury SA1 SoC Module User Manual

2.16

QSPI Flash

The QSPI flash can be used to boot the HPS, and to store the FPGA bitstream, ARM application code and
other user data.
2.16.1

QSPI Flash Type

Table 22 describes the memory availability and configuration on the Mercury SA1 SoC module.
Flash Type
S25FL512S
Table 22: QSPI Flash Type
Warning!
Other flash memory devices may be equipped in future revisions of the Mercury SA1 SoC module.
Please check the user manual regularly for updates. Any parts with different speeds and temperature
ranges that fulfill the requirements for the module variant may be used.
2.16.2

Signal Description

The QSPI flash is connected to the HPS pins 29-34 and to the FPGA SPI configuration port. Some of the
signals are available on the module connector, allowing the user to program the QSPI flash from an external
master.
Please refer to Section 3 for details on programming the flash memory.
Warning!
Special care must be taken when connecting the QSPI flash signals on the base board. Long traces or
high capacitance may disturb the data communication between the SoC and the flash device.
2.16.3

QSPI Flash Corruption Risk

There have been cases in which it was observed that the content of the flash device got corrupted. Ac-
cording to Cypress, this issue is caused by power loss during the Write Register (WRR) command. The most
common reason to use the WRR command is to turn the QUAD bit ON or OFF - this operation takes place
usually at the beginning of the boot process. If required, the bootloader code can be adjusted to set the
QUAD bit to a fixed value, without invoking this command during boot.
For additional information on this issue, please refer to the Cypress documentation and forum discussions
[25], [26].
2.17

SD Card

An SD card can be connected to the HPS_GPIOs available on the module connector. This allows the Mercury
SA1 SoC module to boot from the SD card, as well as data access after booting. Information on SD card
boot is available in Section 3.7.
D-0000-402-002
Size
512 Mbit
30 / 49
Manufacturer
Cypress (Spansion)
Version 06, 16.02.2021