WI.232FHSS-25-R datasheet(57/67 Pages) RADIOMETRIX

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WI.232FHSS-25-R/ WI.232FHSS-250-R DATASHEET

Revision 1.1.0

5. Using Configuration Registers

5.1. CMD Pin

The CMD pin is used to inform the module where incoming UART information should be routed. When the

CMD pin is high or left floating, all incoming UART information is treated as payload data and transferred

over the wireless interface. If the CMD pin is low, the incoming UART data is routed to the command

parser for processing. Since the module’s processor looks at UART data one byte at a time, the CMD line

must be held low for the entire duration of the command plus a 20

μs margin for processing. Leaving the

CMD pin low for additional time (for example, until the ACK byte is received by your application) will not

adversely affect the module. If RF packets are received while the CMD line is active, they are still

processed and presented to the module’s UART for transmission.

The CMD pin is also used during the module startup process to determine whether or not to reload the

non-volatile registers with factory defaults. The module startup or boot process is executed when the

module is powered on from a power off state, or is issued a software or hardware reset. When the module

goes through this boot process, it checks the state of the CMD pin. If it is low, the module will clear the

non-volatile registers and re-populate them with factory default values. Possible reset sources that could

cause the module to reboot are power supply brown-out, power supply instability, noise present on

C2CK/RST pin, noise/voltage spikes on digital I/O pins, issuing a reset command through the command

interface, and toggling the C2CK/RST pin when not in deep sleep.

Figure 15: Command and CMD Pin Timing

5.2. CMD_RSP Pin

The CMD_RSP pin can be used to determine whether the outbound UART traffic is actual data or a

response from the command interpreter. This pin is normally high. When the module responds to a serial

command, such as a register read or write, the pin is pulled low for the duration of the outbound command

response. Monitoring of this pin is optional. It should be tied to a CMOS input or left floating.

5.3. Command Formatting

The Wi.232FHSS module contains several volatile and non-volatile registers that control its configuration

and operation. The volatile registers all have a non-volatile mirror register that is used to determine the

Chapter

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