LPC1786FBD208,551 NXP Semiconductors, LPC1786FBD208,551 Datasheet - Page 58

• Manufacturer Part Number: LPC1786FBD208,551
• Description: Processors - Application Specialized CORTEX-M3 256KB FL 80KB SRAM 4KB EE USB
• Manufacturer: NXP Semiconductors
• Series: LPC17xxr

Specifications of LPC1786FBD208,551

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 120MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, LCD, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 165
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 80K x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x12b, D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 208-LQFP
• Lead Free Status / Rohs Status: Details
• Other names: 935291855551

NXP Semiconductors
LPC178X_7X
Objective data sheet
7.28.1 Features
7.28 Quadrature Encoder Interface (QEI)
7.29 ARM Cortex-M3 system tick timer
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/2
Table 8.
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.
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.
PWM resolution
6 bit
8 bit
10 bit
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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.
PWM speed at operating frequency 120 MHz
All information provided in this document is subject to legal disclaimers.
Rev. 2 — 27 May 2011
n
(see
Table
8).
PWM speed
1.875 MHz
0.468 MHz
0.117 MHz
32-bit ARM Cortex-M3 microcontroller
LPC178x/7x
© NXP B.V. 2011. All rights reserved.
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