QSPI flash timing issue in LPC546xx

[prasannanaik]

Hi,

   I am using LPC546 development board OM13092 for evaluation of QSPI flash. I have used "spifi_dma_transfer" driver example code as reference. I have toggled port PIO2_0 for timing verification. All the settings are same as  "spifi_dma_transfer" code only port pin has been toggled in the code for timing verification.

While checking the driver example code i had following observations:

1) 1 sector erase time: 3.64 msec            

GPIO_PinWrite(GPIO, 2, 0, 1);/*PORT PIN HIGH*/
/* Write enable */
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[WRITE_ENABLE]);
/* Set address */
SPIFI_SetCommandAddress(EXAMPLE_SPIFI, 0U);
/* Erase sector */
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[ERASE_SECTOR]);

/* Check if finished */
check_if_finish();

GPIO_PinWrite(GPIO, 2, 0, 0);/*PORT PIN LOW*/

2) 1 sector write time: 2.24 msec

GPIO_PinWrite(GPIO, 2, 0, 1);/*PORT PIN HIGH*/

while (page < (SECTOR_SIZE / PAGE_SIZE))
{
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[WRITE_ENABLE]);
SPIFI_SetCommandAddress(EXAMPLE_SPIFI, page * PAGE_SIZE);
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[PROGRAM_PAGE]);
xfer.data = g_buffer;
xfer.dataSize = PAGE_SIZE;
SPIFI_TransferSendDMA(EXAMPLE_SPIFI, &handle, &xfer);
while (!finished)
{
}
finished = false;
page++;
check_if_finish();
}
GPIO_PinWrite(GPIO, 2, 0, 0);/*PORT PIN LOW*/

3) 1 sector erase and then write time: 47 msec

GPIO_PinWrite(GPIO, 2, 0, 1);/*PORT PIN HIGH*/
/* Write enable */
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[WRITE_ENABLE]);
/* Set address */
SPIFI_SetCommandAddress(EXAMPLE_SPIFI, 0U);
/* Erase sector */
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[ERASE_SECTOR]);

/* Check if finished */
check_if_finish();

/* Program page */
while (page < (SECTOR_SIZE / PAGE_SIZE))
{
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[WRITE_ENABLE]);
SPIFI_SetCommandAddress(EXAMPLE_SPIFI, page * PAGE_SIZE);
SPIFI_SetCommand(EXAMPLE_SPIFI, &command[PROGRAM_PAGE]);
xfer.data = g_buffer;
xfer.dataSize = PAGE_SIZE;
SPIFI_TransferSendDMA(EXAMPLE_SPIFI, &handle, &xfer);
while (!finished)
{
}
finished = false;
page++;
check_if_finish();
}
GPIO_PinWrite(GPIO, 2, 0, 0);/*PORT PIN LOW*/

Why is the sector erase and write time so high?

Thanks and best regards,

Prasannna

[xiangjun_rong]

Hi, Prasanna,

I suggest you use different GPIO to test the erase time and program time  lest you confuse erase and program time.

BR

XiangJun Rong

[xiangjun_rong]

Hi, Prasanna,

For your issue to test the erasing/programming time, I develop an example to use CTimer to test the erasing and programming time based on my LPC54618 board. Pls refer to the attached code.

The section(4KB) erasing time is tick number is (3981018-6947)*(1/12000000)=330mS, the section programming time is (4244825-3981018)=21uS.

Hope it can help you

BR

Xiangjun Rong

[prasannanaik]

Hi xiangjun.rong‌,

   There is a huge difference between your result and mine.Your method seems the most accurate one. Is there anything wrong wih my procedure?. Iam using high resolution Digital oscilloscope for timing measurement.

Thanks and best regards,

Prasanna

[xiangjun_rong]

Hi, Prasanna,

Regarding your question, as you know that the SPI flash MX25R6435FM2IL0 is used on OM13092, you can download the data sheet of the spi flash from the link:

http://www.macronix.com/Lists/Datasheet/Attachments/7428/MX25R6435F,%20Wide%20Range,%2064Mb,%20v1.4.... 

The erasing/programming time is dependent on the spi flash itself rather than the processor.

Pls refer to following figure, you can see that sector erase time is from 40ms to 240ms, you test the sector erasing time as 47ms, it is okay.

Hope it can help you

BR

XiangJun Rong

[prasannanaik]

Hi xiangjun.rong‌,

   Thanks for your help.

   The datasheet helps in understanding the 47 msec time but why am i getting 3.64 msec sector erase time when i am just testing the sector erase as mentioned in case 1 of  my query. Even that time should be 40 msec ?

Thanks and best regards,

Prasanna

[xiangjun_rong]

Hi, Prasanna,

I suspect you test the wrong elapsing time with GPIO timing for the flash erasing/programming time, can you use a Timer to get the accurate tick number?

BR

Xiangjun Rong