RM42 and MibSPI port

Anthony Boulard said:

Hi everyone !

I have some question about RM42 microcontroler and its MibSPI port :

1] What's the difference between MibSPI and regular SPI port ?

HW: SPI - your application need to take care of the transmit and receive data each time it arrives.

MibSPI - you can group a bunch of data, after they finish the transmit/receive, take care of them together.

It saves lots of CPU wait/load/save time.

2] Can I use the MibSPI port as a regular SPI port ?

HW: Yes

3] Do MibSPI pins are independent ? I explain, If I enable MibSPI port and use it for SPI communication with one slave (CS[0] select the slave), can I use CS[1], CS[2] and CS[3] as GPIOs, as it's write in the following datasheet ?

HW: Yes

Thanks,

Regards,

Anthony.

Anthony,

Just to add a little more about the MibSPI.  It's more than just a SPI with a buffer.

The MibSPI has various transfer groups that can be configured to perform SPI transfers:

  a) on demand  (cpu triggered)

  b) periodically  (time triggered, by internal counter)

  c) even triggered (by input event from another peripheral)

So you can also make it do things like:

  a) poll an external sensor chip every 1ms and copy the results into MibSPI RAM.   Then the CPU just needs to read the MibSPI RAM when it wants the sensor value rather than initiating an SPI transfer.

  b) get data from an external A/D converter at a time that is triggered based on an event coming from the N2HET, so the sample time can be related to when a PWM triggers, for example.

It has 8 of these transfer groups, so it can 'multitask' in some sense.