I found my problem.
THis device only supports 128 byte writes. One needs to get to a 128
byte boundary and then send 128 bytes of data. Unsent bytes will be
undefined.
Actually Atmel support guided me through all this. Good Job Atmel.
And thanks to all who replied.
gm
Reply by Mark Borgerson●April 23, 20052005-04-23
In article <1114294834.754098.71240@l41g2000cwc.googlegroups.com>,
george.martin@att.net says...
> These EEPROMs store system information and are constantly changing. So
> I need the 100K writes of EEPROM.
>
> What is Serail FLASH???
>
If you need lots of frequent updates, you might investigate the
SPI Ferro-Electric RAM (FRAM) from RAMTRON.
Mark Borgerson
Reply by GMM50●April 23, 20052005-04-23
I think I'm doing this but...
To write enable the devices, should I do a WREN (write enable 8 bit
command) then WRSR (write Status Reg 16 bit command) or in the
opposite order?
I don't always see the WEN bit set in the statyus registers?????????
Some days yes today no.
I can see the status going busy after the above sequence.
I read all ones.
THanks
george
Reply by GMM50●April 23, 20052005-04-23
These EEPROMs store system information and are constantly changing. So
I need the 100K writes of EEPROM.
What is Serail FLASH???
george
Reply by Spen●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 Richard Willis●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
> 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
>
> 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 GMM50●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 Grant Edwards●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?