SCT Scout SC4415, User Manual

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2.5.2 IO Details
There are three main IO groups that are available on the IO Interface, APIO, GPIO, and TRIG. Each of the IO groups is
explained in detail below.
APIO: The APIO pins refer to Application Specific Input-Output. These pins are under control of the
selected software application and perform dedicated functions. The user does not have direct
control over the state or function of the APIO pins. Refer to Section 3.3 for more details about the
function of the APIO pins for each application mode.
GPIO: The GPIO pins refer to General Purpose Input-Output. These pins are available to the user at all
times and each pin can be configured using the programming interface as either an input or an
output. As an output, pins can be set to either a logic high or a logic low state. As an input, the
current logical state present on the pin can be read. Refer to Section 5.1
for information on the
software interface for the GPIO pins.
TRIG: The TRIG pins refer to Trigger Input-Output. The direction and function of each trigger pin is
described in Table 2.5.2-1 below.
PIN Description Section
TRIG1 Input trigger, logical OR with TRIG2 Section 3.2.4 and 5.1.10
TRIG2 Input trigger, logical OR with TRIG1 Section 3.2.4 and 5.1.10
TRIG3 Output Trigger Section 5.1.11
Table 2.5.2-1 - TRIG IO Functionality
All of the IO Interface pins have built in protection to ensure that the SC4415 is protected against accidental voltage
surges such as Electrostatic Discharge (ESD). Table 2.5.2-2 lists the electrical specifications for the IO Interface.
Description Value Condition
Operating range 0V – V
IO
Absolute limit -0.5V min, 4.6V max
Typical capacitance 5.0pF
Input transition rate 5ns/V max
Output current, per IO ±8mA, ±20mA V
IO
= 1.2V, V
IO
= 3.3V
Output current, all IO 100mA max V
IO
Internal ( VIO > 0)
Output current, all IO 20mA max V
IO
External ( VIO = 0)
Table 2.5.2-2 – IO Electrical Specifications
Applying a voltage greater than the V
IO
reference for an extended period of time can cause
permanent damage to the device.
2.5.3 VIO
The IO Voltage reference pins, VIO, are used to establish an IO reference between the Scout and the connected
devices. VIO can be configured as either an input (supplied externally) or an output (generated internally) using the
programming interface and the
VIO command.
When VIO is configured as an output, the on board voltage generation is enabled and provides the user with the ability
to set VIO to 1.2V, 1.8V, 2.5V or 3.3V. Alternatively, VIO can be configured as an input to accept an externally provided
voltage which may be generated from other equipment. Table 2.5.3-1 provides the electrical specifications for VIO.
Description Value
Input Operating range 0.8V – 3.5V
Output set-points 1.2V, 1.8V, 2.5V, 3.3V