The tinyARM is the microcontroller module.
in this diagram the PWR RENN is a no-connect, it is not used.
the docs are not on their site, but the package is a 40 pin dip
package. That does not mean all 40 pins are used. One of
them might not connect to anything on their module.
The RSTN_OUT pin appears to be some type of output that is
supposed to drive the reset pins of any other parts you have
on your board. This is based on the circuit connection with the
RSTN pin.