Issue: When the memory-mapped flash region is accessed while the flash
read mode is disabled (fctrl.en flag is clear), the SPI flash controller
generates an invalid response on the D channel.
This may cause the TileLink bus to deadlock.
Workaround: Software should avoid accessing the memory-mapped flash
region when the SPI controller is not in the flash read mode.
Issue: Configuring the frame length to certain values causes incorrect
operation.
Symptoms: Certain frame lengths result in the master sending one extra
clock pulse. The slave device may then become desynchronized.
Workaround: The following frame lengths are supported and can be used.
Do not use other frame lengths.
* Serial mode: 0, 2, 4, 6, 8
* Dual mode: 0, 1, 3, 5, 7, 8
* Quad mode: 0, 1, 2, 3, 5, 6, 7, 8
Issue: The output enable signal for DQ[3] is not driven properly.
Symptoms: Output data from master to slave is not properly transmitted
in quad mode. Data received from the slave is unaffected.
Workaround: When interfacing with SPI flash devices, do not use the
"Quad Input/Output Fast Read" command (opcode 0xEB) while in the
Extended SPI protocol. Do not use the Native Quad SPI protocol.
Albert OuandGitHub