Winbond W25Q Driver
jazzed
Posts: 11,803
This thread is started for W25Q Quad bit SPI Flash driver collaborative development and testing.
Why is this important?
W25QXX is a SPI Flash device that supports accessing up to 4 bits of data at a time and a 2MByte chip is available in S08 for less than $2.50. The highest density availabe DIP8 is 1MB.
Using 2 of the devices side by side, a 10 pin interface can be used for large and fast non-volatile instruction storage allowing up to 22 Propeller pins free for general purpose usage. A 10 bit Flash interface will be at least 10 times faster than a single bit SPI Flash such as used on C3.
Using Flash with Propeller makes sense with the right software because it would allow more HUB RAM to be used by the user for Video buffers, etc.... Certain languages like C could take advantage of this via cache drivers on Propeller today and more languages will be ported (Spin as BigSpin, Javelin JVM, and flavors of Basic).
A separate SPIN application will be needed for using the WQ25 parts as an instruction store. The same SPIN application would include a device driver that can demonstrate more typical SPIN usage.
The upcoming SpinSocket-Flash module (and others) will be using 2 W25QXX devices for allowing access to 4MB of data. To make such hardware useful, a device driver must be developed.
This project is already completed without the benefit of other's contributions.
About Flash:
Generally speaking, Flash is like an EEPROM except that it is reprogrammable block by block. Many higher write cycle reliability EEPROM are actually Flash that allows small block operations. Flash is used in many successful micro-controllers. Flash (invented by Masuoka in 1984 as an employee of Toshiba) has been used in mission critical applications such as Internet Routers and other devices. Flash is constantly used as an all electrical alternative to low MTBF mechanical disk drives. Flash is ubiquitous today because of it's low cost and high reliability.
Why is this important?
W25QXX is a SPI Flash device that supports accessing up to 4 bits of data at a time and a 2MByte chip is available in S08 for less than $2.50. The highest density availabe DIP8 is 1MB.
Using 2 of the devices side by side, a 10 pin interface can be used for large and fast non-volatile instruction storage allowing up to 22 Propeller pins free for general purpose usage. A 10 bit Flash interface will be at least 10 times faster than a single bit SPI Flash such as used on C3.
Using Flash with Propeller makes sense with the right software because it would allow more HUB RAM to be used by the user for Video buffers, etc.... Certain languages like C could take advantage of this via cache drivers on Propeller today and more languages will be ported (Spin as BigSpin, Javelin JVM, and flavors of Basic).
A separate SPIN application will be needed for using the WQ25 parts as an instruction store. The same SPIN application would include a device driver that can demonstrate more typical SPIN usage.
The upcoming SpinSocket-Flash module (and others) will be using 2 W25QXX devices for allowing access to 4MB of data. To make such hardware useful, a device driver must be developed.
This project is already completed without the benefit of other's contributions.
About Flash:
Generally speaking, Flash is like an EEPROM except that it is reprogrammable block by block. Many higher write cycle reliability EEPROM are actually Flash that allows small block operations. Flash is used in many successful micro-controllers. Flash (invented by Masuoka in 1984 as an employee of Toshiba) has been used in mission critical applications such as Internet Routers and other devices. Flash is constantly used as an all electrical alternative to low MTBF mechanical disk drives. Flash is ubiquitous today because of it's low cost and high reliability.
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