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2005-12-07 by smoutpatrick
Hi, What would be the consequences if my hardware design based on the LPC2214 uses 16 bit flash devices that only supports 16 bit accesses? Can I write bytes in the flash using the __packed type modifier? Thanks for the feedback, Patrick Smout
2005-12-08 by Tom Walsh
smoutpatrick wrote: >Hi, > >What would be the consequences if my hardware design based on the >LPC2214 uses 16 bit flash devices that only supports 16 bit accesses? >Can I write bytes in the flash using the __packed type modifier? > >Thanks for the feedback, > > > That would be solely dependant on your Flash. Look to your datasheet on the Flash device. TomW -- Tom Walsh - WN3L - Embedded Systems Consultant http://openhardware.net, http://cyberiansoftware.com "Windows? No thanks, I have work to do..." ----------------------------------------------------
2005-12-08 by Ken Wada
This is emminently doable...A few issues to concern your self though: 1. Make sure you have boot-up code in your internal FLASH, (if you are using the LPC2214). With this boot-up code, you can setup your external memory parameters, (wait-states, burst mode params, address decode etc). 2. If you are using a FLASH-less part, then you MUST use the correct bus-width for the defaults for each memory bank..otherwise your system will not work at all! Plus, you need to make sure you have some boot code already resident on your external FLASH. 3. Make absolutely sure your BCFGn register is properly setup for external FLASH operation. 4. Your external FLASH will inherently run slower than the internal FLASH. Therefore, get as much boost as possible by picking the correct NOR-FLASH, and try as much as possible to get nibble-mode or burst mode...this will greatly improve the performance of your system with little increases in the unit cost of your system. 5. Last but not least, make sure your hardware is wired up properly.. .Byte select lines, chip select etc... Ken Wada --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > Hi, > > What would be the consequences if my hardware design based on the > LPC2214 uses 16 bit flash devices that only supports 16 bit accesses?
> Can I write bytes in the flash using the __packed type modifier? > > Thanks for the feedback, > > Patrick Smout >
2005-12-08 by smoutpatrick
Ken, We have selected a flash that supports page mode. However, the device doesn't support byte access. Is it nevertheless possible to write bytes with the help of the compiler (i.e. the __packed type modifier)? Thanks for your feedback, Patrick --- In lpc2000@yahoogroups.com, "Ken Wada" <kwada@a...> wrote: > > This is emminently doable...A few issues to concern your self though: > > 1. Make sure you have boot-up code in your internal FLASH, (if you > are using the LPC2214). With this boot-up code, you can setup your > external memory parameters, (wait-states, burst mode params, address > decode etc). > > 2. If you are using a FLASH-less part, then you MUST use the correct > bus-width for the defaults for each memory bank..otherwise your system > will not work at all! Plus, you need to make sure you have some boot > code already resident on your external FLASH. > > 3. Make absolutely sure your BCFGn register is properly setup for > external FLASH operation. > > 4. Your external FLASH will inherently run slower than the internal > FLASH. Therefore, get as much boost as possible by picking the correct > NOR-FLASH, and try as much as possible to get nibble-mode or burst > mode...this will greatly improve the performance of your system with > little increases in the unit cost of your system. > > 5. Last but not least, make sure your hardware is wired up properly..
> .Byte select lines, chip select etc... > > Ken Wada > > --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > > > Hi, > > > > What would be the consequences if my hardware design based on the > > LPC2214 uses 16 bit flash devices that only supports 16 bit > accesses? > > Can I write bytes in the flash using the __packed type modifier? > > > > Thanks for the feedback, > > > > Patrick Smout > > >
2005-12-08 by smoutpatrick
--- In lpc2000@yahoogroups.com, Tom Walsh <tom@o...> wrote: > > smoutpatrick wrote: > > >Hi, > > > >What would be the consequences if my hardware design based on the > >LPC2214 uses 16 bit flash devices that only supports 16 bit accesses? > >Can I write bytes in the flash using the __packed type modifier? > > > >Thanks for the feedback, > > > > > > > That would be solely dependant on your Flash. Look to your datasheet on > the Flash device. > > TomW > > -- > Tom Walsh - WN3L - Embedded Systems Consultant > http://openhardware.net, http://cyberiansoftware.com > "Windows? No thanks, I have work to do..." > ---------------------------------------------------- > Tom, what should i look for in the datasheet? The datasheet tells me that no byte access is supported (see original posting). My guess is that the compiler might help me but I'm not sure. Patrick
2005-12-08 by Ken Wada
Yes, it is possible to write bytes! What you need to do, is to read the entire 16-bit word, modify the byte, (upper or lower), then write the entire 16-bit word back into the flash device. Ken Wada --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > Ken, > > We have selected a flash that supports page mode. > However, the device doesn't support byte access. > Is it nevertheless possible to write bytes with the help of the > compiler (i.e. the __packed type modifier)? > > Thanks for your feedback, > > Patrick > > --- In lpc2000@yahoogroups.com, "Ken Wada" <kwada@a...> wrote: > > > > This is emminently doable...A few issues to concern your self > though: > > > > 1. Make sure you have boot-up code in your internal FLASH, (if you > > are using the LPC2214). With this boot-up code, you can setup your > > external memory parameters, (wait-states, burst mode params, > address > > decode etc). > > > > 2. If you are using a FLASH-less part, then you MUST use the > correct > > bus-width for the defaults for each memory bank..otherwise your > system > > will not work at all! Plus, you need to make sure you have some > boot > > code already resident on your external FLASH. > > > > 3. Make absolutely sure your BCFGn register is properly setup for > > external FLASH operation. > > > > 4. Your external FLASH will inherently run slower than the > internal > > FLASH. Therefore, get as much boost as possible by picking the > correct > > NOR-FLASH, and try as much as possible to get nibble-mode or burst > > mode...this will greatly improve the performance of your system > with > > little increases in the unit cost of your system. > > > > 5. Last but not least, make sure your hardware is wired up > properly.. > > .Byte select lines, chip select etc... > > > > Ken Wada > > > > --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > > > > > Hi, > > > > > > What would be the consequences if my hardware design based on the
> > > LPC2214 uses 16 bit flash devices that only supports 16 bit > > accesses? > > > Can I write bytes in the flash using the __packed type modifier? > > > > > > Thanks for the feedback, > > > > > > Patrick Smout > > > > > >
2005-12-08 by Ken Wada
Byte accesses on these 16-bit FLASH devices are not a problem! From what I can tell, you are most likely using an Intel 16-bit wide StrataFlash, or one of those Micron 16-bit wide, (very much like the Intel NOR-StrataFlash). The issues are: 1. You can do all reads as a 16-bit device, (just configure your BCFGn register properly for 16-bit bus 2. To write bytes to this device, you just read the 16-bit value, modify the upper, or lower byte, and write the value back. 3. From what I can tell, the only real reason you need to write to this device is to download the code...in this case, you do not need to concern yourself with byte accesses at all! Just do everything using unsigned short data types. 4. If your BCFGn register is properly configured, your code will run just fine from the external FLASH device....provided you burned it properly. 5. Don't forget to make sure your interrupt vectors are setup properly, otherwise nothing will work. This is one of the small caveats on using external FLASH for the LPC devices. Ken Wada --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > > --- In lpc2000@yahoogroups.com, Tom Walsh <tom@o...> wrote: > > > > smoutpatrick wrote: > > > > >Hi, > > > > > >What would be the consequences if my hardware design based on the > > >LPC2214 uses 16 bit flash devices that only supports 16 bit > accesses? > > >Can I write bytes in the flash using the __packed type modifier? > > > > > >Thanks for the feedback, > > > > > > > > > > > That would be solely dependant on your Flash. Look to your > datasheet on > > the Flash device. > > > > TomW > > > > -- > > Tom Walsh - WN3L - Embedded Systems Consultant > > http://openhardware.net, http://cyberiansoftware.com > > "Windows? No thanks, I have work to do..." > > ---------------------------------------------------- > > > Tom, > > what should i look for in the datasheet? > The datasheet tells me that no byte access is supported (see original
> posting). > My guess is that the compiler might help me but I'm not sure. > > Patrick >
2005-12-11 by smoutpatrick
--- In lpc2000@yahoogroups.com, "Ken Wada" <kwada@a...> wrote: Ken, thanks for the feedback. Regarding topic 5°, any differences in vector setup between using internal flash and external flash (did use the 2106 before)? Patrick > > Byte accesses on these 16-bit FLASH devices are not a problem! From > what I can tell, you are most likely using an Intel 16-bit wide > StrataFlash, or one of those Micron 16-bit wide, (very much like the > Intel NOR-StrataFlash). > > The issues are: > 1. You can do all reads as a 16-bit device, (just configure your > BCFGn register properly for 16-bit bus > 2. To write bytes to this device, you just read the 16-bit value, > modify the upper, or lower byte, and write the value back. > 3. From what I can tell, the only real reason you need to write to > this device is to download the code...in this case, you do not need to > concern yourself with byte accesses at all! Just do everything using > unsigned short data types. > 4. If your BCFGn register is properly configured, your code will run > just fine from the external FLASH device....provided you burned it > properly. > 5. Don't forget to make sure your interrupt vectors are setup > properly, otherwise nothing will work. This is one of the small > caveats on using external FLASH for the LPC devices. > > Ken Wada > > --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > > > > > --- In lpc2000@yahoogroups.com, Tom Walsh <tom@o...> wrote: > > > > > > smoutpatrick wrote: > > > > > > >Hi, > > > > > > > >What would be the consequences if my hardware design based on the > > > >LPC2214 uses 16 bit flash devices that only supports 16 bit > > accesses? > > > >Can I write bytes in the flash using the __packed type modifier?
> > > > > > > >Thanks for the feedback, > > > > > > > > > > > > > > > That would be solely dependant on your Flash. Look to your > > datasheet on > > > the Flash device. > > > > > > TomW > > > > > > -- > > > Tom Walsh - WN3L - Embedded Systems Consultant > > > http://openhardware.net, http://cyberiansoftware.com > > > "Windows? No thanks, I have work to do..." > > > ---------------------------------------------------- > > > > > Tom, > > > > what should i look for in the datasheet? > > The datasheet tells me that no byte access is supported (see > original > > posting). > > My guess is that the compiler might help me but I'm not sure. > > > > Patrick > > >
2005-12-12 by Ken Wada
--- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote: > > --- In lpc2000@yahoogroups.com, "Ken Wada" <kwada@a...> wrote: > > Ken, > > thanks for the feedback. Regarding topic 5°, any differences in > vector setup between using internal flash and external flash (did use > the 2106 before)? 2106? The 2106 does not support an external address or data bus. Anyway...to answer your question. Yes, there are differences in setting up interrupts between using internal vs. external flash. In my case, I setup the system such that there really are no differences at all. This is because; in my system, I copy the vectors, (code) into internal RAM, and execute from all the ISR's from the internal RAM. In this way, I only need to deal with how to get the system to properly vector into internal RAM for execution. Getting code to execute from internal RAM is not a problem with most compiler toolchains. Basically, for the Keil, I use the ERAM directive. This allows me to place the code into RAM on startup. The Keil toolchain basically takes care of the details here. Ken Wada > > Patrick > > > > > Byte accesses on these 16-bit FLASH devices are not a problem! From > > what I can tell, you are most likely using an Intel 16-bit wide > > StrataFlash, or one of those Micron 16-bit wide, (very much like > the > > Intel NOR-StrataFlash). > > > > The issues are: > > 1. You can do all reads as a 16-bit device, (just configure your > > BCFGn register properly for 16-bit bus > > 2. To write bytes to this device, you just read the 16-bit value, > > modify the upper, or lower byte, and write the value back. > > 3. From what I can tell, the only real reason you need to write to > > this device is to download the code...in this case, you do not need > to > > concern yourself with byte accesses at all! Just do everything > using > > unsigned short data types. > > 4. If your BCFGn register is properly configured, your code will > run > > just fine from the external FLASH device....provided you burned it > > properly. > > 5. Don't forget to make sure your interrupt vectors are setup > > properly, otherwise nothing will work. This is one of the small > > caveats on using external FLASH for the LPC devices. > > > > Ken Wada > > > > --- In lpc2000@yahoogroups.com, "smoutpatrick" <sonpat@b...> wrote:
> > > > > > > > > --- In lpc2000@yahoogroups.com, Tom Walsh <tom@o...> wrote: > > > > > > > > smoutpatrick wrote: > > > > > > > > >Hi, > > > > > > > > > >What would be the consequences if my hardware design based on > the > > > > >LPC2214 uses 16 bit flash devices that only supports 16 bit > > > accesses? > > > > >Can I write bytes in the flash using the __packed type > modifier? > > > > > > > > > >Thanks for the feedback, > > > > > > > > > > > > > > > > > > > That would be solely dependant on your Flash. Look to your > > > datasheet on > > > > the Flash device. > > > > > > > > TomW > > > > > > > > -- > > > > Tom Walsh - WN3L - Embedded Systems Consultant > > > > http://openhardware.net, http://cyberiansoftware.com > > > > "Windows? No thanks, I have work to do..." > > > > ---------------------------------------------------- > > > > > > > Tom, > > > > > > what should i look for in the datasheet? > > > The datasheet tells me that no byte access is supported (see > > original > > > posting). > > > My guess is that the compiler might help me but I'm not sure. > > > > > > Patrick > > > > > >