ThingMagic Mercury6e M6e-30dBm, Руководство по оборудованию

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Hardware Interfaces
Hardware Overview
19
General Purpose Input/Output (GPIO)
The four GPIO connections, provided through the
M6e Digital Connector Signal Definition
,
may be configured as inputs or outputs using the MercuryAPI. The GPIO pins connect
through 100 ohm resistors to the high current PA0 to PA3 pins of the AT91SAM7X
processor. The processor data sheet can be consulted for additional details.
Pins configured as inputs must not have input voltages that exceed voltage range of -0.3
volts to +5.5 volts. In addition, during reset the input voltages should not exceed 3.3V.
Outputs may source and sink 16 mA. Voltage drop in the series 100 ohm resistor will
reduce the delivered voltage swing for output loads that draw significant current.
Input Mode
– TTL compatible inputs,
– Logic low < 0.8 V,
– Logic high > 2.0V.
– 5V tolerant
Output Mode
– 3.3 Volt CMOS Logic Output with 100 ohms in series.
– Greater than 1.9 Volts when sourcing 8 mA.
– Greater than 2.9 Volts when sourcing 0.3 mA.
– Less than 1.2 Volts when sinking 8 mA.
– Less than 0.2 Volts when sinking 0.3 mA.
Module power consumption can be adversely affected by incorrect GPIO configuration.
Similarly, the power consumption of external equipment connected to the GPIOs can also
be adversely affected. The following instructions will yield specification compliant
operation.
On power up, the M6E module configures its GPIOs as outputs to avoid contention from
user equipment that may be driving those lines. The input configuration is as a 3.3 volt
logic CMOS input and will have a leakage current not in excess of 400 nA. The input is in
an undetermined logic level unless pulled externally to a logic high or low.
Module power
consumption for floating inputs is unspecified . With the GPIOs configured as inputs
and individually pulled externally to either high or low logic level, module power
consumption is as listed in the
M6e Power Consumption
table.
GPIOs may be reconfigured individually after power up to become outputs. This
configuration takes effect either at API execution or a few tens of milliseconds after power
up if the configuration is stored in nonvolatile memory. The configuration to outputs is