Figure 12. Wakeup-In Line - Motorola g20 Developer's Manual

4.10.2.1 Sleep Mode AT Commands
The following are the Sleep mode AT commands:
• ATS24: Activates/disables Sleep mode.
The g20 receives a request to activate or deactivate Sleep mode.
• ATS102: Sets the value of the delay before sending data to the terminal.
The g20 receives the value to define the duration (in ms.) of the delay for waking up the terminal.
• AT+MSCTS: The UART's CTS line control.
The g20 receives a request to define the behavior of the CTS line when the g20 is in Sleep mode. It enables or disables
activation of the CTS line after wakeup.
4.10.2.2 Sleep Mode HW Signals
Two HW lines are used:
• One for waking the g20 (Wakeup-In)
• One for waking the terminal (Wakeup-Out)
4.10.2.2.1 Terminal Does Not Wake the g20 (If the Terminal Uses Hardware Flow Control Only)
When the g20 is in Sleep mode, the CTS line is also inactive. The terminal does not send any characters to the g20 if the CTS
is inactive, otherwise the character may be lost (Hardware Flow Control).
4.10.2.2.2 Terminal Wakes the g20 Using the Wakeup-In Line
The terminal uses the Wakeup-In line (pin #16) to wake up the g20 when it wants to send data. When the Wakeup-In line is low,
the g20 will not enter the Sleep mode. If the terminal has data to send while the g20 is sleeping, it activates the line (brings it to
active low), then waits 30 ms (the time required to wake the g20). Only then can the terminal start sending data.
Two modes exist:
• Idle Mode: The terminal has no data to send. If the terminal enables sleep mode (using ats24), the g20 activates its Sleep
mode module.
• Wakeup Mode: The g20 does not enter sleep mode, and the terminal can send data.
Once the terminal changes the line edge to Wakeup mode, it needs a 30 ms delay before sending any data to the g20 (using the
RS232 protocol).
98-08901C68-O
TXD
Line (pin #21)
WAKEUP-IN
Line (pin #16)
Idle
Wakeup
30 ms

Figure 12. Wakeup-In Line

Data transmit
AT Commands Reference
191