Hello: I'm starting up a new desing using 4 Atmel AT25HP512 devices connected to a 4 wire SPI interface. My question is does anyone have an over view (pseudo code) of hew to Initialize Read Write Enable Write These devices. I've got all the C code writen but I'm missing something Thanks In Advance. George
SPI Serial EEPROM design
Started by ●April 20, 2005
Reply by ●April 20, 20052005-04-20
On 2005-04-20, GMM50 <george.martin@att.net> wrote:> Hello: > > I'm starting up a new desing using 4 Atmel AT25HP512 devices connected > to a 4 wire SPI interface. > > My question is does anyone have an over view (pseudo code) of hew to > Initialize > Read > Write Enable > Write > > These devices. I've got all the C code writen but I'm missing > somethingDoesn't the data sheet explain it? I'm using Atmel IIC EEPROMs at the moment, so I don't have the SPI version data sheets handy, but the last time I used Atmel SPI EEPROMs, the data sheet explained exactly what you needed to do. -- Grant Edwards grante Yow! "THE LITTLE PINK at FLESH SISTERS," I saw them visi.com at th' FLUROESCENT BULB MAKERS CONVENTION...
Reply by ●April 20, 20052005-04-20
Grant Edwards wrote:> On 2005-04-20, GMM50 <george.martin@att.net> wrote: > >>Hello: >> >>I'm starting up a new desing using 4 Atmel AT25HP512 devices connected >>to a 4 wire SPI interface. >> >>My question is does anyone have an over view (pseudo code) of hew to >> Initialize >> Read >> Write Enable >> Write >> >>These devices. I've got all the C code writen but I'm missing >>something > > > Doesn't the data sheet explain it? > > I'm using Atmel IIC EEPROMs at the moment, so I don't have the > SPI version data sheets handy, but the last time I used Atmel > SPI EEPROMs, the data sheet explained exactly what you needed > to do. >It helps to have a logic analyzer hooked up so that you can check your signals against the datasheet.
Reply by ●April 20, 20052005-04-20
On 2005-04-20, Jim Stewart <jstewart@jkmicro.com> wrote:>>>I'm starting up a new desing using 4 Atmel AT25HP512 devices >>>connected to a 4 wire SPI interface. My question is does anyone >>>have an over view (pseudo code) of hew to Initialize Read Write >>>Enable Write These devices. I've got all the C code writen but >>>I'm missing something >> >> Doesn't the data sheet explain it? >> >> I'm using Atmel IIC EEPROMs at the moment, so I don't have the >> SPI version data sheets handy, but the last time I used Atmel >> SPI EEPROMs, the data sheet explained exactly what you needed >> to do. > > It helps to have a logic analyzer hooked up > so that you can check your signals against > the datasheet.A 4-channel digital scope will works just as well. A 2-channel scope is a bit more cumbersome, but will do in a pinch. -- Grant Edwards grante Yow! I wonder if I ought at to tell them about my visi.com PREVIOUS LIFE as a COMPLETE STRANGER?
Reply by ●April 20, 20052005-04-20
Well I'm more stuck in how to unlock the device. It powers up with writes disabled. I've read the data sheets and it metions that I need to set the control register and issue a write enable command. But the details are vague. And the order of these in not at all clear. These are relative new devices so perhaps I should look at the previous versions data sheet for clues. george
Reply by ●April 21, 20052005-04-21
SST have similar SPI parts. SST25xxxx There is example C code commands available from http://www.sst.com/products.xhtml/serial_flash/ Here's the driver http://www.sst.com/downloads/software_driver/SST25VFxxx.txt JG www.sst.com "GMM50" <george.martin@att.net> wrote in message news:1114027048.627969.259150@o13g2000cwo.googlegroups.com...> Hello: > > I'm starting up a new desing using 4 Atmel AT25HP512 devices connected > to a 4 wire SPI interface. > > My question is does anyone have an over view (pseudo code) of hew to > Initialize > Read > Write Enable > Write > > These devices. I've got all the C code writen but I'm missing > something > > Thanks In Advance. > George >
Reply by ●April 21, 20052005-04-21
Also check out http://www.sst.com/downloads/app_note/S72051.pdf "GMM50" <george.martin@att.net> wrote in message news:1114027048.627969.259150@o13g2000cwo.googlegroups.com...> Hello: > > I'm starting up a new desing using 4 Atmel AT25HP512 devices connected > to a 4 wire SPI interface. > > My question is does anyone have an over view (pseudo code) of hew to > Initialize > Read > Write Enable > Write > > These devices. I've got all the C code writen but I'm missing > something > > Thanks In Advance. > George >
Reply by ●April 21, 20052005-04-21
GMM50 wrote:> Well I'm more stuck in how to unlock the device. > It powers up with writes disabled. > I've read the data sheets and it metions that I need to set the control > register and issue a write enable command. > But the details are vague. And the order of these in not at all clear. > > These are relative new devices so perhaps I should look at the previous > versions data sheet for clues. > > george >1) make sure you have the /WP pin pulled or strapped to VCC. 2) send WRSR,0 to enable writing to all blocks (BP0,1). 3) send the WREN instruction. that sets the WEN bit in the status reg. you can read the status reg to see if is setup correctly. BP0,1 should all be low to write-enable all blocks. WEN should be high to enable writing. Hope that helps. - Richard
Reply by ●April 21, 20052005-04-21
"GMM50" <george.martin@att.net> wrote in message news:1114027048.627969.259150@o13g2000cwo.googlegroups.com...> Hello: > > I'm starting up a new desing using 4 Atmel AT25HP512 devices connected > to a 4 wire SPI interface. > > My question is does anyone have an over view (pseudo code) of hew to > Initialize > Read > Write Enable > Write > > These devices. I've got all the C code writen but I'm missing > something > > Thanks In Advance. > George >Forgive me for being slightly off topic but have you not thought about replacing the eeprom with serial flash ? Regtards Spen
Reply by ●April 23, 20052005-04-23