QPI mode on S25FS512S

[GoKa_4003631]

Hi,

I have tried to configure the SPI-NOR flash to QPI mode by configuring CR2V with value 0x48.

After doing this I am trying to read the Read Quad Identification (RDQID AFh), It is not giving the valid value,

Please help me in QPI mode enter and exit scenarios.

[SudheeshK]

Hi,

Did you read and verify that QPI bit is set in configuration register before RDQID operation?

Can you provide SPI waveform for RDQID operation?

You can disable QPI mode by clearing bit 6 (QPI) of CR2V (volatile configuration register 2) to 0. Please read ID using RDID (single SPI mode) after disabling QPI mode and check if you receive correct data from our device. You can find more details about volatile and non-volatile registers from our knowledge base article, Volatile and Non-Volatile Registers in Serial Flash Devices – KBA228310 .

Thanks and Regards,

Sudheesh

[GoKa_4003631]

Hi Sudheesh,

Thanks for your reply, please find the my observations inline.

Did you read and verify that QPI bit is set in configuration register before RDQID operation?

I have tried to read the configuration register2 but it was showing all 0xFF.

Read configuration Register sequence:

Address with opcode:0x3008065 (CMD (RDAR):0x65, ADDR(3B):0x800003), 4-line format

Dummy:4B :0xFFFFFFFF (8-cycles), 4-line format

Read : 1B in 4-lane format

I ensured the Configuration Register2 write sequence is fine by writing with 0x20 and read back the Configuration Register2 in single mode it has given the value 0x20

Can you provide SPI waveform for RDQID operation?

We don't have the signals routed out to capture the waveform.

Regards,

Goutham

[GoKa_4003631]

Hi Sudheesh,

Is there any other settings to enter QPI mode along with setting CR2V[6] to 1, protection related?

Is this device supports the (1-4-4) page programming, In the datasheet found only 1PP and 4PP?

Regards,

Goutham Kumar.

[SudheeshK]

Hi Goutham Kumar,

To enable QPI mode (4-4-4), you need to set the QPI bit in configuration register 2 to 1. When you enable QPI mode by writing 1 to CR2[6], QUAD bit in configuration 1 (CR1[1]) will also get enabled automatically. There are no other configurations required to enable QPI mode.

Please note, once QPI mode is enabled our device will support command, address and data only in 4-4-4 format. So, if you try to read in single SPI mode (1-1-1) after enabling QPI mode, our device will not respond to it. If you want to use 1-1-1 or 1-4-4 formats, then you have to disable QPI mode by clearing bit 6 in volatile configuration register 2 (CR2V). As you can see from the datasheet, all bits in non-volatile configuration register 2 (CR2NV) are OTP (one time programmable). So, if you programmed any of the bits in CR2NV, you won't be able to change them back to default value. During operation, flash device will use only the volatile registers (volatile registers get initialized from non-volatile registers upon power up).

Our device support 1-4-4 format, please see 'Quad I/O Read' operation explained on page 91 of datasheet https://www.cypress.com/file/216376/download . To use this format, you have to disable QPI mode and enable QUAD mode by writing 1 to bit 1 of configuration register 1. When the device is in QUAD mode (not QPI), it will support both QUAD and Single SPI commands.

Could you please double check the below sentence that you mentioned?

"I ensured the Configuration Register2 write sequence is fine by writing with 0x20 and read back the Configuration Register2 in single mode it has given the value 0x20". Flash device will not respond to single SPI commands if QPI mode is enabled.

Can your provide your source code to access our flash device? We can review it and let you know if there are any issues.

Thanks and Regards,

Sudheesh

[GoKa_4003631]

Hi Sudheesh,

I understand the scenario you had explained in the previous reply, and I am following the same sequence to enter QPI mode.

After entering to the QPI mode, the device is responding well to RDID(9Fh), WREN(06h) and WRDS(04h), commands, But when I am trying RDQID(AFh), - given the response as 0xFFFFFFFF

Software reset sequence (66h +99h ) - reset is not happening device is being still in QPI mode Only (not responding to single SPI commands)

Could you confirm that this spansion part support the Quad Page programming like Quad I/O Read.

we are not using source code of project, we have scripts which sends the commands serially over the QSPI lines, Could you please share to me, If you have any source code where these sequences are available

Regards,

Goutham Kumar.

[SudheeshK · Accepted solution]

Hi Hi Goutham Kumar,

Our device S25FS512S does not support Quad Page Program command. This legacy command (Quad Page Program) is replaced by page program operation in QPI (4-4-4) mode.

You can refer our low level driver for serial flash devices available at: https://www.cypress.com/documentation/software-and-drivers/low-level-driver-spi-flash?source=search&... for more details about the command sequences.

To get a better understanding about your issue, can you please provide logic analyzer waveform for RDID and RDQID operations?

Thanks and Regards,

Sudheesh