Two Issues with PICbasic's Efficiency

[Melanie]

It is a feature of SERIAL EEPROM like the internal PIC EEPROM or external EEPROM (like the 24LC64 and similar etc) that require (up to) 10mS for a WRITE operation (consult the Datasheet of the EEPROM you are using for the actual timing). All the worlds fastest Assembly routines will not help you. You must use a faster hardware product like Alain suggested.

[Normnet]

Or else, M25P32 from ST ...

I believe ST sold the M25P line to Numonyx and the line has been upgraded to the faster M25PE... series.
See the M25PE80 for a sample data sheet.
It's rated at writing 256 bytes in 11 ms.
For M25P code example see M25P32 (warning other compiler).

A full 256 byte per write is probably required however.
Since only erase can convert 0 to 1's overwriting previous of new and following of new bytes with 1's can simulate a one byte write.
Perhaps a low priority interrupt could do the 256 byte write in the background.


Norm

[Normnet]

M25PE80... The memory can be written or programmed 1 to 256 bytes at a time.

Improved over old M25P series?
I found with the previous M25P series after many 1 byte writes errors crept
in thus a full 256 byte sector write was used.

Norm

[hankshone]

Improved over old M25P series?
I found with the previous M25P series after many 1 byte writes errors crept
in thus a full 256 byte sector write was used.

Norm

Thanks Norm the your suggestions and the sample codes. IN the manual it sounds like 1~256 is a flexiable range that can be written. Any way I will try it out later.

[hankshone]

It is a feature of SERIAL EEPROM like the internal PIC EEPROM or external EEPROM (like the 24LC64 and similar etc) that require (up to) 10mS for a WRITE operation (consult the Datasheet of the EEPROM you are using for the actual timing). All the worlds fastest Assembly routines will not help you. You must use a faster hardware product like Alain suggested.

Sounds good. The EEPROMs require a 5ms wirting circle typically from Microchips. While it can be reduced to about 3ms as I tried.