S42/Central Software User Guide
1VV0301318 Rev. 3
– 2018-08-31
Reproduction forbidden without written authorization from Telit Communications S.p.A.- All Rights Reserved.
Page 42 of 66
6.4.1.
Drive from "interface up" to "interface down" State
Once a de-asserted IUR-OUT# signal of the initiator is detected by the acceptor, the acceptor
shall confirm that signal by de-asserting its IUC-OUT# signal which is connected to the IUC-
IN# signal of the initiator.
After the initiator detects a de-asserted IUC-IN# signal both devices go into "interface down"
state and can enable MCU power saving mechanisms.
During MCU power saving, the MCU can switch off the UART but shall be able to detect an
IUR# assert.
UICP State
interface up
pending interface down
interface down
IUR-OUT#
IUC-IN#
RTS/CTS UART Hardware flowcontrol
UART-TXD
data
t1
t2
de-asserted
asserted
de-asserted
asserted
t1
>= 100ms (see this chapter)
t2
< 1s
