LPC1777 View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
LPC1777
NXP Semiconductors.
'LPC1777' PDF : 120 Pages View PDF
NXP Semiconductors
LPC178x/7x
32-bit ARM Cortex-M3 microcontroller
PWM to immediately release all motor drive outputs. At the same time, the motor control
PWM is highly configurable for other generalized timing, counting, capture, and compare
applications.
The maximum PWM speed is determined by the PWM resolution (n) and the operating
frequency f: PWM speed = f/2n (see Table 8).
Table 8. PWM speed at operating frequency 120 MHz
PWM resolution
PWM speed
6 bit
1.875 MHz
8 bit
0.468 MHz
10 bit
0.117 MHz
7.28 Quadrature Encoder Interface (QEI)
Remark: The QEI is available on parts LPC1788/87/86 and LPC1778/77/76
A quadrature encoder, also known as a 2-channel incremental encoder, converts angular
displacement into two pulse signals. By monitoring both the number of pulses and the
relative phase of the two signals, the user can track the position, direction of rotation, and
velocity. In addition, a third channel, or index signal, can be used to reset the position
counter. The quadrature encoder interface decodes the digital pulses from a quadrature
encoder wheel to integrate position over time and determine direction of rotation. In
addition, the QEI can capture the velocity of the encoder wheel.
7.28.1 Features
• Tracks encoder position.
• Increments/decrements depending on direction.
• Programmable for 2 or 4 position counting.
• Velocity capture using built-in timer.
• Velocity compare function with “less than” interrupt.
• Uses 32-bit registers for position and velocity.
• Three position compare registers with interrupts.
• Index counter for revolution counting.
• Index compare register with interrupts.
• Can combine index and position interrupts to produce an interrupt for whole and
partial revolution displacement.
• Digital filter with programmable delays for encoder input signals.
• Can accept decoded signal inputs (clk and direction).
• Connected to APB.
7.29 ARM Cortex-M3 system tick timer
The ARM Cortex-M3 includes a system tick timer (SYSTICK) that is intended to generate
a dedicated SYSTICK exception at a 10 ms interval. In the LPC178x/7x, this timer can be
clocked from the internal AHB clock or from a device pin.
LPC178X_7X
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 5.5 — 26 April 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
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