Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
10/03/08 00:14
Read: times


 
#158780 - SPI Slave Response
Responding to: ???'s previous message
Hi All,

If I can share an experince... I had a 32bit micro as master SPI and a 32bit processor as a slave SPI. (Never again I say!)

SPI worked when the clock was slow, but faster SPI clock rates data was corrupted.

We found out the SPI slave was not repsonding fast enough.

In essence.... the SPI slave micro.... must respond like hardware SPI chips (immedatley)... and the slave micro can not afford to be executing a critical loops while SPI data is being clocked in....

On the slave We ended up making the SPI interupt the highest interupt priority... and all other services were polled.

Joe


List of 54 messages in thread
TopicAuthorDate
SPI slave            01/01/70 00:00      
   high speed?            01/01/70 00:00      
      sory for late replay.            01/01/70 00:00      
         SPI clock            01/01/70 00:00      
            not sure..            01/01/70 00:00      
               the worst possible approach            01/01/70 00:00      
                  SPI Slave Response            01/01/70 00:00      
                     further explanation?            01/01/70 00:00      
                        Fixed speed            01/01/70 00:00      
                        SPI Timing Diagrams            01/01/70 00:00      
                           UART Mode 0 - SPI like Serial Shif register            01/01/70 00:00      
                              uhm            01/01/70 00:00      
                           to joe            01/01/70 00:00      
                  your point?            01/01/70 00:00      
                     you can't fail with software master            01/01/70 00:00      
   Unanswerable!            01/01/70 00:00      
      really?            01/01/70 00:00      
         Intended for/usable for not always identical            01/01/70 00:00      
            consideration?            01/01/70 00:00      
   Some Questions            01/01/70 00:00      
      whichever you choose            01/01/70 00:00      
         low cost?            01/01/70 00:00      
            if you do not use an interrupt            01/01/70 00:00      
               polling?            01/01/70 00:00      
                  bits/s not packet size            01/01/70 00:00      
                     speed?            01/01/70 00:00      
                        bits/s not packet size!            01/01/70 00:00      
                           500ms?            01/01/70 00:00      
                        here            01/01/70 00:00      
                           Yes - I agree            01/01/70 00:00      
                              issues            01/01/70 00:00      
                                 UART!            01/01/70 00:00      
                              Not complex - just requiring low baudrate            01/01/70 00:00      
                                 kind of rcorrect            01/01/70 00:00      
                                    Complexity contra recommendable            01/01/70 00:00      
                                       answer            01/01/70 00:00      
                              as i said            01/01/70 00:00      
                                 lots of them            01/01/70 00:00      
                                 mcu with spi, right here in the thread            01/01/70 00:00      
                           CodeArchitect. ?            01/01/70 00:00      
                              no            01/01/70 00:00      
                                 ahhh            01/01/70 00:00      
      simulating SS?            01/01/70 00:00      
         Interrupts are slower than tight polling            01/01/70 00:00      
            wow            01/01/70 00:00      
               all about worst-case            01/01/70 00:00      
                  thanks...            01/01/70 00:00      
                     missed interrupts            01/01/70 00:00      
                        correct me..            01/01/70 00:00      
                           Fast interrupts            01/01/70 00:00      
                              thanks...            01/01/70 00:00      
                                 An Alternative...            01/01/70 00:00      
                                    Some Descriptive Information            01/01/70 00:00      
   AT89LP2052 has HW SPI            01/01/70 00:00      

Back to Subject List