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hrg
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SPI EEPROM interface

Hi Dialog Team

1) The boot time of I2C EEPROM seems to be too long(approx 3 sec) .does the SPI -EEPROM also takes the same amount of time ? We dont want to use SPI flash since it needs more than 2 volts to operate (we need to use 1.8 volt operatable memory which takes less boot time ) !

2) If i use SPI EEPROM (ATMEL AT25M01) ,is there any changes to be done in SPI Flash driver provided by the Dialog ? If so ,it would be great if you provide us some support. I had gone through the pheriperal drivers,examples ,interfacing application notes ,but i couldnt find any info about SPI EEPROM.

3) Or is there any way to reduce the three second boot time while using I2C EEPROM ? (is it possible through secondary bootloader ?? )

Thankyou

JE_Dialog
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Hello hrg,

Hello hrg,

The limitation here is EEPROM : it is fundamentally taking much longer  .  Please note there are 1.8V flash devices on the market and we have qualified a 1.8V device from Adesto , the AT25XE011. Also ,the boot time is only a problem if you are using deep sleep frequently : if you use extended sleep, then SRAM is kept alive so the boot is effectively only on a system power remove/apply scenario so the 3s is a one-off. There is very little difference in quiesecent current : extended sleep is 1.2uA and deep sleep is approx 0.6uA.

 We only qualified an i2c EEPROM since the vast majority of customers are using FLASH due to the time issue you note . THose that do use EEPROM is just small amounts , say 2K to store link info.

BR JE_Dialog

hrg
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Hello JEDialog

Hello JEDialog

If we use SPI based EEPROM will it take the same 3 seconds boot time like I2C EEPROM ???

JE_Dialog
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Hello hrg, if you use SPI

Hello hrg, if you use SPI EEPROM it will have similar timing to the FLASH - the limitation is the bus speed of i2c vs SPI  (please see page 6 , table 2 of the apps note below). The bus speed is limited on i2c so secondary boot loader won't help here.

http://support.dialog-semiconductor.com/system/files/resources/AN-B-023%20-%20DA14580%20interfacing%20with%20external%20memory%20v1.4.pdf

We haven't qualified any SPI EEPROM, but the team tell me that as long as you adhere to the timing specifications , it should work just fine.

BR JE_Dialog

hrg
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Thankyou JE_Dialog

Thankyou JE_Dialog
So mostly i can use the SPI driver provided by the dialog in order to make the SPI EEPROM to work right?? or any driver modifications is to be done in the driver ???

JE_Dialog
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Hello hrg, without testing it

Hello hrg, without testing it, we believe it should work fine assuming the hadware timing specifications comply : you would need to test it though.

BR JE_Dialog

hrg
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Thankyou JE_Dialog . I will

Thankyou JE_Dialog . I will test once and reply you if i face any problems .

hrg
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HI Dialog Team

HI Dialog Team

I tried interfacing SPI EEPROM AT25M01 and check using pheriperal example via uart. The SPI flash driver provided is based on winbond AT25M01.While comparing the datasheets ,there was no much difference except erase procedure in winbond.But still couldnt able to read or write to the EEPROM . Could you please mention changes or modifications to be done in order to acess SPI EEPROM .