IMP003 Can SPI FLASH connections be shared with other SPI devices?

Hardware
1

I would like to connect following signals to IMP003.

  • wake from sleep with a button (pinW)
  • SPI (sensor)
  • I2C (sensor)
  • UART hardware flow control
    I cannot find a pin assignment that can do this.
    Can SPI FLASH connections be shared with other SPI devices? Any other suggestion?
2

The Pin Mux page has the imp003 GPIO pin out.

The imp003 has 2 UARTs with flow control, 2 IC2 buses, and 2 SPI buses (outside of the SPI FLASH) to work with!

3

I know. It’s awesome! But try to make the pin assignment. Not possible, right? Can SPI FLASH connections be shared with other SPI devices?

4

You cannot use the SPI flash’s SPI bus for other SPI devices.

Couldn’t you use:

spi - ABCE
i2c - FG
uart - DGUV
wake - W

5

No, G is in both i2c and uart…
I have to give up something else
Thanks

6

So it is, my mistake.

7

Can I ask what kind of ICs you’re using? Typically you can get away with 1 directional flow control.

If that’s all you need, you can configure your UART first, then configure a SPI or I2C bus that uses one of the UART pins after, and will take control of that pin.

8

Can you elaborate a bit on the 1 directional flow control. I prefer to connect all sensors to IMP. But I could also connect the I2C device to the other processor connected over uart.

Yes, I could first configure for uart, then for i2c and then configure back to uart. However the I2C has a 10k pull up and I’m not sure if uart still works this way

9

Sharing the I2C data line is likely fine, as long as the clock line stays stable during UART usage (and neither is every used at the same time).

1-directional flow control is sometimes possible because generally one side of a serial link is the one sending more data and hence the one that needs the flow control to stop it every now and then.

Bit-banging I2C if you have no bandwidth requirements is also possible, allowing you to put i2c on any two pins.