CP316: Microprocessor Systems and Interfacing
Introduction to the QwikFlash Development Board
To get a microcontroller operational, three subcircuits are always
power, clock, and reset. This lab investigates the reset subcircuit.
- The PIC18Fxx2 differentiates between eight different types of
listed in section 3.0 Reset of the data sheet.
In the simplest cases,
the system resets on
Locate the microcontroller clear pin,
or the reset switch
on the QwikFlash
board schematic. Sketch the reset circuit in your lab notebook and note the
resistor values. Locate this circuit on the physical board.
- power up, referred to as Power-on
- external reset typically initiated from a reset
Reset during normal operation.
- To ensure an internal Power-on Reset signal,
the input signal must meet the VPOR (VDD Start
Voltage) and SVDD (VDD Rise Rate)
Find these values in the electrical characteristics section,
of the datasheet.
Also locate the Voltage on
with respect to VSS and
pay special attention to Note 2. Explain how the reset circuit works as (a)
a power up reset and (b) an external reset. How is note 2 used? Explain how
the VPOR (VDD Start Voltage) is met.
Show your calculations.
Demonstration - explain the components involved in the
and their location in the schematic and the physical board.
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