SPI-EEPROM read problem

Started by tech...@gmail.com in comp.arch.embedded13 years ago

hello members I'm looking for some sample codes that interface TMS320F2812 with a SPI-EEPROM. The EEPROM I'm using is from Microchip and...

hello members I'm looking for some sample codes that interface TMS320F2812 with a SPI-EEPROM. The EEPROM I'm using is from Microchip and has a "1024 x 8-bit organization " and "16 byte page " I'm using some sample codes from TI themselves that actually implement the read and write function without page wrapping. That runs as is on my Dev. Board. I've been able to tamper with the cur...


refreshing RAM from EPROM

Started by GG in comp.arch.embedded15 years ago 2 replies

I'm working on a project where they implemented a data store in EEPROM and a copy of it in RAM. The RAM copy is updated all the time and a low...

I'm working on a project where they implemented a data store in EEPROM and a copy of it in RAM. The RAM copy is updated all the time and a low priority task writes it back to EEPROM. There is also a task that eery once in a while copies back from EEPROM to it's RAM shadow. I can't understand why someone would want to do that - if it is to overcome corruption, isn't it better to reset the ...


CRC calculation for variables stored in eeprom

Started by ssubbarayan in comp.arch.embedded12 years ago 7 replies

Dear all, I have posted a couple of months back about eeprom corruption and some experts here adviced me to stored a CRC value for the...

Dear all, I have posted a couple of months back about eeprom corruption and some experts here adviced me to stored a CRC value for the memory contents to determine corruption.Regarding this I have got a query: In our case,the contents in the eeprom change dynamically in run time.Does that mean everytime we need to update the CRC too?As an end user how would I know which value of CRC is ...


custom VID/PID help

Started by milappatel in comp.arch.embedded11 years ago 1 reply

can anybody help me...? I hv 1 FT232BM chip and EEprom 93lc46. I am configuring my EEPROM using Eprog 3.0 software. In that I do change...

can anybody help me...? I hv 1 FT232BM chip and EEprom 93lc46. I am configuring my EEPROM using Eprog 3.0 software. In that I do change with my own VID and PID both and downloading it to EEPROM. and change the FTdibus.inf / Ftdiport.inf file with both VID and PID. but the problem is everytime my PC detect the same comport COM6 at all my 4 USB ports. but when I erase and set the defaul...


Writing 9 bits in a sequence to perform Soft Reset

Started by ssubbarayan in comp.arch.embedded13 years ago

Hi all, This is again a follow up on EEPROM discussion I had previously a few days back.Regarding I2C based EEPROM I recently came across...

Hi all, This is again a follow up on EEPROM discussion I had previously a few days back.Regarding I2C based EEPROM I recently came across an application note from Microchip company (Document name AN709). The note says : "FORCING INTERNAL RESET VIA SOFTWARE In all designs it is recommended that a software reset sequence be sent to the EEPROM as part of the microcontrollers power up sequenc...


Problems reading data EEprom on Pic 16F88

Started by Simon in comp.arch.embedded15 years ago 10 replies

I have been trying to use the read data EEPROM feature of the 16F88, but can't get it to work. I have used the sample code from Microchip's...

I have been trying to use the read data EEPROM feature of the 16F88, but can't get it to work. I have used the sample code from Microchip's datasheet. Attached is the (entire) ASM file that I am using. It should (I had hoped) store the value h'BB' in the register count1. Then read it from the data EEPROM location (h'20') and store it into the register count2. When I step through it in...


Read-While-Write Flash memory

Started by pozz in comp.arch.embedded3 years ago 9 replies

Linked to my previous post, here I'd like to discuss another topic related to persistent variables. Some years ago I used microcontrollers...

Linked to my previous post, here I'd like to discuss another topic related to persistent variables. Some years ago I used microcontrollers with internal EEPROM memory or I used external serial I2C EEPROM to save persistent variables. It seems to me the scenario has recently changed. With new Cortex-M microcontrollers, internal EEPROM is typically absent, but the manufacturer explain...


EEPROM guarantees after power loss during a write

Started by John Devereux in comp.arch.embedded12 years ago 30 replies

Hi, I am wondering what guarantees are there for existing EEPROM data, after power is lost during a write operation? I am writing a...

Hi, I am wondering what guarantees are there for existing EEPROM data, after power is lost during a write operation? I am writing a datalogging routine that writes records to an EEPROM. It's an Atmel 24C1024, although the question is probably applicable to other devices too. This uses "page mode" for writes - the device seems to be organised as 256 byte pages. Say power is lost during...


MPC8260 - I2C - single channel 1-wire master (DS2482) - 1 wire EEPROM (DS2433)

Started by Anonymous in comp.arch.embedded15 years ago 4 replies

Hi, I'm writing an I2C driver for the MPC8260 that needs to read/write to a 1-wire EEPROM via a single channel 1-wire master. Since I'm new...

Hi, I'm writing an I2C driver for the MPC8260 that needs to read/write to a 1-wire EEPROM via a single channel 1-wire master. Since I'm new to the embedded world, I was wondering, if I want to send a READ ROM command to the 1 wire EEPROM, how must I go about doing that via software? How must I format the Tx buffer of the I2C to send that out to the 1-wire EEPROM via the single-channel 1-...


Read EEPROM Memory on a mc9s12dg256 from Motorola

Started by Anonymous in comp.arch.embedded15 years ago 1 reply

Hi ! I have to write an EEPROM driver for an mc9s12dg256 from Motorola. Everything is fine, but i cant find a command ro read from the...

Hi ! I have to write an EEPROM driver for an mc9s12dg256 from Motorola. Everything is fine, but i cant find a command ro read from the eeprom memory. There are commands for Writing and erasing, but no Command for reading the memory. The Documentation from Motorola is real bad. Please help ! THX


Serial Flash vs Serial EEPROM ( sorry of you see the message twice)

Started by elil in comp.arch.embedded8 years ago

Dear, I'd like to understand why ALL Serial Flash chips always come with SPI vs Serial EEPROM chips that always come with I2C ? Why not vice...

Dear, I'd like to understand why ALL Serial Flash chips always come with SPI vs Serial EEPROM chips that always come with I2C ? Why not vice versa for example? For my current project I'd like to add a small external memory, let's say 16 kBytes, as a backup for some case. Writing to EEPROM is too slow, 5 msec for 8 bytes, wheres Flash is good, but it comes with SPI = 5 PINS: SCK, MISO,MOSI,...


EEPROM cell failures

Started by antares in comp.arch.embedded15 years ago 1 reply

Hello, does anybody know when an EEPROM cell failure caused by too many writings is detect? when I write a value and immediately after...

Hello, does anybody know when an EEPROM cell failure caused by too many writings is detect? when I write a value and immediately after the writng I read it or after some time? thank you


PIC EEPROM EEIF flag polarity

Started by Anonymous in comp.arch.embedded13 years ago 5 replies

Just wondering if someone could suggest a workaround for this snippet of pseudo code: if ( eeif == 1 ) { eeif = 0 // write...

Just wondering if someone could suggest a workaround for this snippet of pseudo code: if ( eeif == 1 ) { eeif = 0 // write eeprom } This piece of code (written in assembly) goes into the main loop of my program and allows the main loop to continue executing while the EEPROM takes its leisurely 8ms to write. The problem is that on power-up eeif == 0, and this code can never ...


eeprom problems

Started by leilei in comp.arch.embedded11 years ago 2 replies

Hi, is there any documents instruct how to read data from eeprom, like 93c46? I have 93c46's datasheet and source code from linux rtl8139...

Hi, is there any documents instruct how to read data from eeprom, like 93c46? I have 93c46's datasheet and source code from linux rtl8139 driver, but I still can not understand the detail.


i2c eeprom.c driver supports 2 address bytes?

Started by Anonymous in comp.arch.embedded12 years ago 4 replies

I have a i2c eeprom device (Microchip 24LC65) that has 2 bytes for the device address (this is the 2 bytes that come right after the...

I have a i2c eeprom device (Microchip 24LC65) that has 2 bytes for the device address (this is the 2 bytes that come right after the control byte). The eeprom.c driver seems to handle devices that has only 1 byte for the device address. Has anyone configured the eeprom driver for devices that needs 2 bytes for its addressing? I am working on a IXP425 board. The i2c algo is i2c-algo-bits.c. ...


Why Serial Flash has SPI, but Serial EEPROM - I2C ?

Started by elil in comp.arch.embedded8 years ago 4 replies

Dear, I'd like to understand why ALL Serial Flash chips always come with SPI vs Serial EEPROM chips that always come with I2C ? Why not vice...

Dear, I'd like to understand why ALL Serial Flash chips always come with SPI vs Serial EEPROM chips that always come with I2C ? Why not vice versa for example? For my current project I'd like to add a small external memory, let's say 16 kBytes, as a backup for some case. Writing to EEPROM is too slow, 5 msec for 8 bytes, wheres Flash is good, but it comes with SPI = 5 PINS: SCK, MISO,MOSI,...


CY7C68013 remove EEPROM

Started by ewaite in comp.arch.embedded14 years ago 3 replies

Is there an easy software way to remove the vid/pid from the EEPROM and ge back to the initial Cypress one? Thanks Eric This...

Is there an easy software way to remove the vid/pid from the EEPROM and ge back to the initial Cypress one? Thanks Eric This message was sent using the comp.arch.embedded web interface o www.EmbeddedRelated.com


PIC 18F4520 SPI with Serial EEPROM

Started by Patrick Johnson in comp.arch.embedded14 years ago 2 replies

I am attempting to communicate with a 25LC256 serial (SPI) EEPROM with a 18F4520. I have successfully communicated with this same EEPROM with...

I am attempting to communicate with a 25LC256 serial (SPI) EEPROM with a 18F4520. I have successfully communicated with this same EEPROM with a 18F4431 using the same code. The code I am using is as follows: MEM_CS = 0; SSPBUF = 0x02; while(SSPSTATbits.BF != 1); SSPBUF = AddressHigh; while(SSPSTATbits.BF != 1); SSPBUF = AddressLow; while(SSPSTATbits.BF != 1); SSPBUF = DataByte; ...


Reading EEPROM data, ATMEGA16, with imagecraft c-compiler

Started by fabrizio in comp.arch.embedded15 years ago 2 replies

Hei all, The intension is to read out a table located in EEPROM using the imagecraft C-compiler version 6.31A Definition in...

Hei all, The intension is to read out a table located in EEPROM using the imagecraft C-compiler version 6.31A Definition in C --------------- #pragma data:eeprom char Output_Ports_Table[] = { 0x38, 0x02}; #pragma data:data .. .. In the program i write following code ... ... unsigned char Table_Contents; EEPROM_READ((int)&Output_Ports_Table[0], Table_Contents); Tab...


question on ARM comparing to AVR

Started by cutemonster in comp.arch.embedded13 years ago 2 replies

I have experience developing 8051 but I'm very new to ARM comparing to AVR. My question is how ARM save data since it doesn't have built in...

I have experience developing 8051 but I'm very new to ARM comparing to AVR. My question is how ARM save data since it doesn't have built in eeprom like AVR? I checked many ARM eval board but they all don't have external eeprom. I found a ARM board that completely suit my needs but it doesn't have eeprom. I would think this is normal to every ARM and am I missing something? thanks for an...