David Nguyen

9S12XDP512: Question about the three SPI's

Discussion created by David Nguyen on Mar 15, 2009
Latest reply on Mar 16, 2009 by David Nguyen

I have read the datasheet for the MC9S12XDP512 on the SPI section.  There is only one memory map for the SPI.  Does this mean that if I set the SPE in the in the SPICR1 register, it will turn on all three SPI's of the MCU?  Also, does this mean that they will use the same SPIDR register?

 

If this is the case, then there is no sense in making three SPI ports when I could just connect multiple devices to one SPI port and select each one utilizing the slave select signal.

 

I have tried to look for application notes on this but could not find any.  What I want to know is, are there separate memory maps for each SPI in this MCU so that each SPI could have its own clock rate and its own data line?

 

I appreciate any help.  Thanks.

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