User's Manual

PCS3_HD_v01.000-03
Confidential / Preliminary
Page 26 of 101
2013-10-21
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PCS3 Hardware Interface Description
3.3 Power-Up / Power-Down Scenarios
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3.3.2 Signal States after Startup
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Table 7 describes the various states each interface signal passes through after startup and dur-
ing operation.
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Signals are in an initial state while the module is initializing. Once the startup initialization has
completed, i.e. when the software is running, all signals are in defined state. The state of sev-
eral signals will change again once the respective interface is activated or configured by AT
command (for more information see also Section 3.10.6).
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Table 7: Signal states
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Signal name Power on reset
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Duration appr. 150ms
Startup phase
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Duration appr. 4s
State after first
firmware initialization
After 4-4.5s
RXD0 PD PU O, H
TXD0 PD PD I, PD
CTS0 PD PU O, L
RTS0 PD PD I, PD
DTR0 PD PU I, PU
DCD0 PD PU
1
O, H
DSR0 PU PU O, L
RING0 PU PU O, H
WAKEUP PD PD PD
LCI_IND PD PD PD
PWR_IND O, L O, L O, L
STATUS PD PD PD
PCM PD PD PD
1.
No external pull down allowed during this phase.
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L = Low level
H = High level
I = Input
O = Output
PD = Pull down resistor with appr. 100k
PD(…k) = Pull down resistor with ...k
PU = Pull up resistor with appr. 100k
PU(…k) = Pull up resistor with ...k