General Purpose Inputs And Outputs - Motorola MTM800 User Manual

THEORY OF OPERATION (TRANSCEIVER)
communicates with the controller via the SPIB bus and the module is activated by
SPIB_CS0_UART.
Furthermore a 32.768 kHz clock signal from the terminal is provided to the GPS module on J0600.
The controller ports SIM UART0 and SIM UART1 are also routed to J0600 in order to provide the
signals for a SIM card device.
SIM card connectivity
All SIM card signals are also available on the connectors, J0450, J0570 and J0600.
EMERGENCY
The signal EMERGENCY has an internal 4k7 pull up to FLT_A+. When the EMERGENCY signal
pulls to ground during the "OFF" state of the terminal, the regulators U0300, U0301 and U0302 are
powered on by means of Q0301 and Q0303. INT_SWB+ is supplied to the terminal through Q0301.
The controller reads the EMERGENCY information via Q0158 when it comes out of the POR and
applies a high signal to SOFT_TURN_OFF and thus keeps the terminal powered on.
When EMERGENCY is applied during the "ON" state of the terminal, the controller also reads the
EMERGENCY information via Q0158.
IGNITION
The IGNITION line is accessible on the 20pin accessory connector J0400 on pin 10 and the 40 pin
expansion board connector J0400 on pin 27.
They are routed to a common 4k7 pull down resistor R0404. When the IGNITION signal exceeds
approx. 4V, the regulators U0300, U0301 and U0302 are powered on by means of Q0302, Q0301
and Q0303. INT_SWB+ is supplied to the terminal through Q0301.
The controller reads the IGNITION information via Q0160 when it comes out of the POR.

General purpose inputs and outputs

HOOK
The HOOK GPIO is used as a digital input with a 2k2 pull up resistor R0154 to 5V. The HOOK
function is detected if the signal is active low.
PA_ENABLE
The PA_ENABLE GPIO is used as a digital input with a 2k2 pull up resistor R0155 to 5V. The
PA_ENABLE function is detected if the signal active low.
EXTERNAL_PTT
The EXTERNAL_PTT GPIO is accessible on the 20 pin accessory connector J0400 on pin 3 and the
12 pin Enhanced Control Head connector J0550 pin 5. They are routed to a common 4k7 pull up
resistor R0160 to 5V. EXTERNAL_PTT is detected if the signal active low.
EXT_ALARM
The EXT_ALARM GPIO is used as a digital output with a 4k7 pull up resistor to FLT_A+. When
EXT_ALARM occurs, the transistor Q0159 switches to low.
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