BGS3 Hardware Interface Description
3.3 Power Up / Power Down Scenarios
63
BGS3_HD_v01.000d
Page 31 of 109
2010-03-26
Confidential / Released
3.3.2
Signal States after Startup
describes the various states each interface signal passes through after startup and dur-
ing operation.
As shown in
and
signals are in an undefined state while the module is initial-
izing. Once the startup initialization has completed, i.e. when the software is running, all signals
are in defined state. The state of the DAI signals will change again once the interface is acti-
vated or configured by AT command.
Abbreviations used in below
L = Low level
H = High level
L/H = Low or high level
I = Input
O = Output
OD = Open Drain
PD = Pull down with min. +15µA and max. +100µA
PD(…k) = Fix pull down resistor
PU = Pull up with typ. -200µA and max. -350µA
PU(…k) = Fix pull up resistor
Table 8:
Signal states
Signal name
Undefined state during
startup
Defined state after
startup initialization
Active state after
configuration by
AT command
DAI
SYNC
O, L
O, L
CCIN
I, PU(100k)
I, PU(100k)
CCRST
O, L
O, L
CCIO
O, L
O, L
CCCLK
O, L
O, L
CCVCC
O, L
2.9V
RXD0
I, PU
O, H
TXD0
I, PU
I, PD(330k)
CTS0
O, L
O, L
1
RTS0
I, PU
I, PD(330k)
DTR0
I, PU
I
DCD0
O, L
O, H
DSR0
O, L
O, L
1
RING0
I, PU
O, H
2
RXD1
O, H
O, H
TXD1
I, PD(330k)
I, PD(330k)
CTS1
L
O, L
1
RTS1
I, PD(330k)
I, PD(330k)
DAI0
I
O, L
O, L
DAI1 I
Tristate
I
DAI2 I
O,
L
3
O, L