LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 51 of 125
Figure 30 shows the case where in addition to the wake-up character further (valid) characters are sent. The
wake up character wakes-up the DCE. The other characters must be sent after the “wake up time” of 20 ms. If
this condition is met, the characters are recognized by the DCE. The DCE is allowed to re-enter idle-mode after
2000 GSM frames from the latest data reception.
CTS OFF
CTS ON
Active mode is held for 2000 GSM frames (~9.2s)
after the last data received
time
Wake up time: up to 15.6 ms
time
TxD
module
input
Wake up character
Not recognized by DCE
Valid characters
Recognized by DCE
Figure 30: Wake-up via data reception with further communication
The “wake-up via data reception” feature can’t be disabled.
The “wake-up via data reception” feature can be used in both AT+UPSV=1 and AT+UPSV=2 case
(when
RTS
line is set to OFF).
In command mode, if autobauding is enabled and HW flow control is not implemented by the DTE, the
DTE must always send a character to the module before the “AT” prefix set at the beginning of each
command line: the first character will be ignored if the module is in active-mode, or it will represent the
wake up character if the module is in idle-mode.
In command mode, if autobauding is disabled, the DTE must always send a dummy “AT” to the module
before each command line: the first character will not be ignored if the module is in active-mode (i.e.
the module will reply “OK”), or it will represent the wake up character if the module is in idle-mode (i.e.
the module won’t reply).
No wake-up character or dummy “AT” is required from the DTE during connected-mode since the
module continues to be in active-mode and doesn’t need to be woken-up. Furthermore in data mode a
wake-up character or a dummy “AT” would affect the data communication.
1.9.1.4
UART application circuits
Providing the full RS-232 functionality (using the complete V.24 link)
For complete RS-232 functionality conforming to
[4] in DTE/DCE serial communication,
the complete UART interface of the module (DCE) must be connected to the DTE as described in Figure 31.