Specifications

XT65/XT75 Hardware Interface Description
3.6 Power Saving
s
XT65_XT75_HD_v01.001 Page 48 of 133 2007-1-8
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3.6.1 Network Dependency of SLEEP Modes
The power saving possibilities of SLEEP modes depend on the network the module is registered in. The paging
timing cycle varies with the base station. The duration of a paging interval can be calculated from the following
formula:
t = 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
0.47-2.12 seconds. The DRX value of the base station is assigned by the network operator.
In the pauses between listening to paging messages, the module resumes power saving, as shown in Figure 10.
Figure 10: Power saving and paging
The varying pauses explain the different potential for power saving. The longer the pause the less power is con-
sumed.
3.6.2 Timing of the CTS0 Signal in CYCLIC SLEEP Mode 7
Figure 11 illustrates the CTS0 signal timing in CYCLIC SLEEP mode 7 (CFUN=7).
Figure 11: Timing of CTS0 signal (if CFUN= 7)
With regard to programming or using timeouts, the UART must take the varying CTS inactivity periods into
account.