Timing Of The Cts Signal In Cyclic Sleep Modes - FALCOM I56 Hardware Description

I65/I56I HARDWARE DESCRIPTION

5.9.5 Timing of the CTS signal in CYCLIC SLEEP modes

The CTS signal is enabled in synchrony with the paging cycle of module. It
goes active low each time when the module starts listening to a paging message
block from the base station. The timing of the paging cycle varies with the base
station. The duration of a paging interval can be calculated from the following
formula:
4.615 ms (TDMA frame duration) * 51 (number of frames) * DRX value.
DRX (Discontinuous Reception) is a value from 2 to 9, resulting in paging
intervals from 0.47 to 2.12 seconds. The DRX value of the base station is
assigned by the network operator. Each listening period causes the CTS signal
to go active low: If DRX is 2, the CTS signal is activated every 0.47 seconds, if
DRX is 3, the CTS signal is activated every 0.71 seconds and if DRX is 9, the
CTS signal is activated every 2.1 seconds. The CTS signal is active low for 4.6
ms. This is followed by another 4.6 ms UART activity. If the start bit of a
received character is detected within these 9.2 ms, CTS will be activated and
the proper reception of the character will be guaranteed.
CTS will also be activated if any character is to be sent.
After the last character was sent or received the interface will remain active
for:
another 2 seconds, if AT+CFUN=5 or 7,
another 10 minutes, if AT+CFUN=6 or 8,
or for an individual time defined with AT^SCFG, if AT+CFUN=9.
Assertion of RTS has the same effect.
In the pauses between listening to paging messages, while CTS is high, the
module resumes power saving and the AT interface is not accessible. See
figure 21 and figure 22.
Figure 21: Timing of CTS signal (example for a 2.12 s paging cycle)
Figure 22 illustrates the CFUN=5 and CFUN=7 modes, which reset the CTS
signal 2 seconds after the last character was sent or received.
This confidential document is the property of FALCOM GmbH and may not be copied or circulated without permission.
VERSION 1.00
Page 49