User's Manual

Embedded Module Reset
40  Digi Connect Wi-EM 9210 Hardware Reference
Embedded Module Reset
Hard Reset
The embedded modules support a hardware reset on pin 10 of the 12-pin header. The unit
will be forced into a hard reset if this pin is pulled low. When used with the development
board, this pin is wired to reset button SW5, which means it acts as a hard reset button.
The JTAG version of the Wi-EM 9210 EM module has a 3-pin jumper (JP1) to allow two
modes of operation.
Shorted 1-2: The CPU and other registers are reset. The PLL, GPIOs, and memory are not.
Debugger connection is maintained. This is the same as SRST# from the debugger.
Shorted 2-3: The entire module is reset. Debugger connection will need to be re-
established.
Soft Reset
NET+OS provides an internal facility to enact a soft reset, but it is the responsibility of a
specific implementation to choose a reasonable trigger to invoke it. One choice is to use a
GPIO pin as a signal to trigger a soft reset. The embedded modules have one GPIO pin
GPIO[13] which is not normally assigned to any other task named "/INIT." It is an ideal
candidate for use as a signal for soft reset. The signal is wired to the push button on the
module (next to the LEDs), and is pulled high unless the button is pushed.
The "naresetapp" sample application demonstrates a simple mechanism for monitoring a
GPIO pin and then initiating a soft reset when the pin achieves a particular value.
Memory
Flash
The Wi-EM 9210 module has 4 MB of flash memory, which is controlled by chip select 2
(default = st_cs1) located at 0x50000000.