PS-SAU-1900E
Mar. 8
th
,1999 (Rev. 0.0)
--- CONFIDENTIAL AND PROPRIETARY ---
33
GPIO_EXPAND_CS line. GPIO_EXPAND_ENAB is then set high and remains in this state until power
down.
To set an output on the bus all 16 bits must be shifted in, therefore when calling the bus it is necessary to
send a mask of the bits which are to remain unchanged, along with the new values of changed bits.
The state of the expansion bus is kept in a global static variable. Any number of bits can be changed
during one call to the gpio_exp_out function. After all 16 bits are clocked in a high to low transition on
GPIO_EXPAND_CS strobes the bits to the outputs.
Sets of bits on the bus that are control lines for certain hardware (B0,B2,BR on the SLIC for example)
have been defined by one mask so that only one call to the gpio_exp_out function is needed.
3.2.5.
Analog Multiplexer (MUX).
An analog multiplexer is utilized to allow more than one input to the BBASIC ADC. The analog mux has
three input select lines which are outputs of the GPIO of MSM.
These select lines determine which line is to be input to the BBASIC ADC.
The MUX currently has six (6) inputs from CDMA Module, Battery management Module.(PA_TEMP,
PA_DET, AC_POWER, MAIN_TEMP, V_BATT, Vref(2.084Volts).
The MUX is initialized to select X4, which a reference voltage to calibrate A/D converter.
ADC INPUT
MUX INPUT
GPIO SETTING
Vref(2.084Volts) X4 GPIO13(2
2
)=1, GPIO12(2
1
)=0, GPIO11(2
0
)=0
AC_MONI X0
GPIO13(2
2
)=0, GPIO12(2
1
)=0, GPIO11(2
0
)=0
MAIN_TEMP
(BATT_TEMP)
X2 GPIO13(2
2
)=0, GPIO12(2
1
)=1, GPIO11(2
0
)=0
V_BATT X3
GPIO13(2
2
)=0, GPIO12(2
1
)=1, GPIO11(2
0
)=1
PA_DET X5
GPIO13(2
2
)=1, GPIO12(2
1
)=0, GPIO11(2
0
)=1
PA_TEMP X7
GPIO13(2
2
)=1, GPIO12(2
1
)=1, GPIO11(2
0
)=1
3.2.6. LED
Indicators.
The user interface consists of three LEDs , IN_SERVICE, POWER, and DISRUPTION.
The DISRUPTION LED is controlled directly by hardware. It indicates ON when any one of a limited
number of internal hardware failures occur.
The IN_SERVICE indicator is controlled by outputs of the gpio_expansion bus. This LED indicates ON if a
CDMA pilot channel has been acquired. This LED will be turned on/off within 10 seconds (maximum) of
the software detecting in service/out of service.
The POWER indicator is also controlled by an output from the gpio_expansion bus, and indicates Battery
power or AC power. LED solidly on indicates the LAU is running from AC power. A flashing LED
indicates that Battery is supplying the power source.
The LEDs are initialized to OFF.
