User's Manual

9 Timing parameters

9.1 Reset behavior

Following a reset, a

CMD_RESET_IND

and a stable low level on the /RTS pin signalizes that

the module is ready for operation. During restart the /RTS may be pulled to GND level for a

short time (<100µs, see ﬁgure

) until it is conﬁgured accordingly by the application on the

module.

9.1.1 Reset via /RESET pin

To force a module restart by means of the /RESET pin, it must ﬁrst be drawn to low for at

least 100µs. After the pin is released, the module will reboot, indicate a

CMD_RESET_IND

Please note that the selected UART baud rate will introduce a latency for transmitting the

5-byte packet at module start-up.

Recommended procedure: After the /RESET pin is released, wait for up to 200ms + UART

transmission time for the

CMD_RESET_IND

packet (value is to be adopted for the selected

UART baud rate) and for the stable low level on the /RTS pin.

This section applies only to a situation where the VCC is stable and the mod-

ule was already running. Additional timings are needed when VCC was just

applied to the module, see chapter

4.2

9.1.2 Reset as result of a serious error condition

If the module runs in a serious error condition, a software reset is executed. In this case, the

module starts up (this includes sending a

CMD_RESET_IND

) automatically and can be used

again. The volatile RuntimeSettings are reset to defaults. Therefore, the host needs to

detect the start-up indication and implement reconﬁgure the module’s volatile settings when

this event was detected.

9.2 Latencies when leaving standby or shutdown

The indication

CMD_RESET_IND

CMD_STANDBY_IND

(5 Bytes in total) are written before the

/RTS pin is pulled back to low level. Therefore, the start-up time is also dependent on the

UART baud rate. The time presented here was measured with the UART default setting of

115200 baud, 8n1.

9.2.1 Wake-up latency from standby

The wake-up time from standby is 1.6 ms.