AC75 Hardware Interface Description
Strictly confidential / Preliminary
s
AC75_HD_V00.202
Page 32 of 120
27.04.2006
3.3.2 Signal States after Startup
Table 6 describes the various states each interface pin passes through after startup and
during operation.
As shown in Figure 5 and Figure 6 the pins are in undefined state while the module is
initializing. Once the startup initialization has completed, i.e. when CTS is high and the
software is running, all pins are in defined state. The state of several pins will change again
once the respective interface is activated or configured by AT command.
Table 6: Signal states
Active state after configuration by AT command
Signal name
Undefined state
during startup
Defined state after
initialization
GPIO
SPI
I
2
C
DAI
SYNC
L
O
CCIN
I, PU(100k)
I, PU(100k)
CCRST
L
O
CCIO
L
O
CCCLK
L
O
CCVCC
L
2.9V
RXD0
I,
PU
O
TXD0
I, PU
I, PD(330k)
CTS0
L
O
RTS0
I, PU
I, PD(330k)
DTR0
I,
PU
I
DCD0
L
O
DSR0
L
O
RING0 I,
PU
O
RXD1
H
O
TXD1
I, PD(330k)
I, PD(330k)
CTS1
L
O
RTS1
I, PD(330k)
I, PD(330k)
SPIDI
I Tristate
I
Tristate
SPICS
I Tristate
O
Tristate
I2CDAT_SPIDO
I O
O
IO
I2CCLK_SPICLK
I O
O
O
GPIO1 I,
PU Tristate IO
GPIO2 I,
PU Tristate IO
GPIO3 I,
PU Tristate IO
GPIO4 I,
PD Tristate IO
GPIO5 L
Tristate IO
GPIO6 I
Tristate IO
GPIO7 I,
PU Tristate IO
GPIO8 L
Tristate IO
GPIO9 I
Tristate IO
GPIO10 I
Tristate
IO
DAC_OUT
L
O
DAI0
I
Tristate
O
DAI1
I
Tristate
I
DAI2
I
Tristate
O
DAI3
I
Tristate
O
DAI4
I
Tristate
I
DAI5
I
Tristate
I
DAI6
I
Tristate
I
For abbreviations, see below.