AC75 Hardware Interface Description
Strictly confidential / Preliminary
s
AC75_HD_V00.202
Page 48 of 120
27.04.2006
3.6.2 Timing of the CTSx Signal in CYCLIC SLEEP Mode 7
Figure 11 illustrates the CTSx signal timing in CYCLIC SLEEP mode 7 (CFUN=7).
Figure 11: Timing of CTSx signal (if CFUN= 7)
With regard to programming or using timeouts, the UART must take the varying CTS
inactivity periods into account.
3.6.3
Timing of the RTSx Signal in CYCLIC SLEEP Mode 9
In SLEEP mode 9 the falling edge of RTSx can be used to temporarily wake up the ME. In
this case the activity time is at least the time set with AT^SCFG="PowerSaver/Mode9/
Timeout",<psm9to> (default 2 seconds). RTSx has to be asserted for at least a dedicated
debounce time in order to wake up the ME. The debounce time specifies the minimum time
period an RTSx signal has to remain asserted for the signal to be recognized as wake up
signal and being processed. The debounce time is defined as 8*4.615 ms (TDMA frame
duration) and is used to prevent bouncing or other fluctuations from being recognized as
signals. Toggling RTSx while the ME is awake has no effect on the AT interface state, the
regular hardware flow control via CTS/RTS is unaffected by this RTSx behaviour.
Figure 12: Timing of RTSx signal (if CFUN = 9)
2 s
CTSx
AT interface disabled
1 character
st
Last character
Beginning of power saving
0.9...2.7 s
0.9...2.7 s
AT interface enabled
2 s
CTSx
AT interface disabled
Wake up of ME
AT interface enabled
RTSx
Debounce Time
37 ms
Power saving
