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Discussion Groups | BasicX | SPIcmd and how BX24 fetch program instructions
Discussion forum for the BasicX family of microcontroller chips.
SPIcmd and how BX24 fetch program instructions - Olle Bengtsson - Feb 19 10:06:12 2009
Hi
I have not been able to figure any good explanation of how BX can avoid
getting the program instructions cluttred when the SPI bus is used.
BX24 is fetching these intructions on the same bus to the EEPROM as is
used to communicate with other devices with SPIcmd.
I guess that when BX need to fetch a program instruction it use another
channel than what is possible to use for external SPI communication.
If so why have is "hole 1" an "EEPROM Chip Select" What is the use of
that one? I not been able to find any information about this.
My problem is this:
I have set up my SPI like this:
OpenSPI(1, SPI_CONFIG, 5) =
channel 1, MSB first, Clock phase false, Clock pin idle HIGH, 1834,2
kHz and pin 5 as chipselect.
I have a large peice of code, filling up allmost all EEPROM (31000kB).
Quite often, 1-4 times per second I use the SPI bus to send 36 bytes of
data to a LED driver. And when I do this it seems that the BX "chokes"
or something - suddenly it cannot perform the PWM requested from
Timer1A and Timer1B and Timer2 ... or the processor suddenly hangs or
otherwise have undeterministic behaviour.
I suspect that the frequent use of the SPI bus kkeep the processor from
fetching program code in a way needed ... Does anyone have other theory?
Should one check the "hole 1" to determine if the BX is using the SPI
bus?
Should I send my 36 bytes is smaller chunks?
Thanks all for any ideas and though about this
/Olle
------------------------------------
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
I have not been able to figure any good explanation of how BX can avoid
getting the program instructions cluttred when the SPI bus is used.
BX24 is fetching these intructions on the same bus to the EEPROM as is
used to communicate with other devices with SPIcmd.
I guess that when BX need to fetch a program instruction it use another
channel than what is possible to use for external SPI communication.
If so why have is "hole 1" an "EEPROM Chip Select" What is the use of
that one? I not been able to find any information about this.
My problem is this:
I have set up my SPI like this:
OpenSPI(1, SPI_CONFIG, 5) =
channel 1, MSB first, Clock phase false, Clock pin idle HIGH, 1834,2
kHz and pin 5 as chipselect.
I have a large peice of code, filling up allmost all EEPROM (31000kB).
Quite often, 1-4 times per second I use the SPI bus to send 36 bytes of
data to a LED driver. And when I do this it seems that the BX "chokes"
or something - suddenly it cannot perform the PWM requested from
Timer1A and Timer1B and Timer2 ... or the processor suddenly hangs or
otherwise have undeterministic behaviour.
I suspect that the frequent use of the SPI bus kkeep the processor from
fetching program code in a way needed ... Does anyone have other theory?
Should one check the "hole 1" to determine if the BX is using the SPI
bus?
Should I send my 36 bytes is smaller chunks?
Thanks all for any ideas and though about this
/Olle
------------------------------------
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )