HAL_QSPI_AutoPolling() fail when polling the SR of NOR flash in QPI mode

[diverger]

Hi,

I'm using STM32H750B with a NOR flash (Winbond's W25128 chip). When the chip is configured as QPI mode. If polling SR1 using the auto polling function, it will throw error. But read SR directly and check the bits works.

Any help? Thanks.

[diverger]

Hi @Imen DAHMEN​ ,

I'm a little confused.

1. The 'dummy' cycles will be insert between the instruction and the data phase (no address phase), right?
2. Why normal read-check method work *only* without dummy clocks?
3. In the DTR datasheet section 8.2.4, it doesn't show instruction 05h need extra dummy cycles in QPI mode, so, is this a undocumented trick?
4. It seems, in QPI mode + auto-polling, the dummy clocks can be larger than 2, such as 4, 10, etc., will work too.

Thanks.

[Imen.D]

Hi @diverger​ ,

When reading with QUADSPI interface in Dual or Quad mode, you should insert at least one dummy cycle, in order to give output signals enought time to switch from output mode to input mode.

You can find this mentionned in Reference Manual section 23.3.3 QUADSPI command sequence "Dummy-cycles phase". This concern any command in Dual or Quad mode.

Even if it worked in indirect mode, for proper usage, you must follow the recommended QUADSPI specification to insert at least a dummy cycle.

In your case you are reading from a memory's status register the memory will always send its status register as long as it is clocked. So inserting dummy cycles will not impact the data transfert.

The QUADSPI will ignore the first status byte sent by the memory (2 dummy cycles) and will read the second one.

Hope it is clear and this brings some help to you.

Imen