基于LPC1311設(shè)計(jì)的Cortex-M3 CPU USB接口方案

NXP LPC1311/13/42/43 是基于Cortex-M3 的微控制器，具有高度集成和低功耗，可用于嵌入式應(yīng)用。CPU工作頻率高達(dá)72MHz，單電源2.0V-3.6V工作，內(nèi)置了嵌套中斷向量控制器(NVIC)，多達(dá)32KB閃存，多達(dá)8KB數(shù)據(jù)存儲(chǔ)器，USB設(shè)備，快速模式I2C總線接口，一個(gè)UART，四個(gè)通用定時(shí)器和多達(dá)42個(gè)GPIO引腳。主要應(yīng)用在電子測(cè)量，照明，告警系統(tǒng)和白色家電。本文介紹了LPC1311/13/42/43主要特性，方框圖，時(shí)鐘發(fā)生方框圖以及自供電USB接口框圖和總線供電USB接口框圖。

The LPC1311/13/42/43 are ARM Cortex-M3 based microcontrollers for embedded applications featuring a high level of integration and low power consumption. The ARM Cortex-M3 is a next generation core that offers system enhancements such as enhanced debug features and a higher level of support block integration.

The LPC1311/13/42/43 operate at CPU frequencies of up to 72 MHz. The ARM Cortex-M3 CPU incorporates a 3-stage pipeline and uses a Harvard architecture with separate local instruction and data buses as well as a third bus for peripherals. The ARM Cortex-M3 CPU also includes an internal prefetch unit that supports speculative branching.

The peripheral complement of the LPC1311/13/42/43 includes up to 32 kB of flash memory, up to 8 kB of data memory, USB Device (LPC1342/43 only), one Fast-mode Plus I2C-bus interface, one UART, four general purpose timers, and up to 42 general purpose I/O pins.

LPC1311/13/42/43主要特性和優(yōu)勢(shì)：

ARM Cortex-M3 processor, running at frequencies of up to 72 MHz.

ARM Cortex-M3 built-in Nested Vectored Interrupt Controller (NVIC).

32 kB (LPC1343/13)/16 kB (LPC1342)/8 kB (LPC1311) on-chip flash programming memory.

8 kB (LPC1343/13)/4 kB (LPC1342/11) SRAM.

In-System Programming (ISP) and In-Application Programming (IAP) via on-chip bootloader software.

Selectable boot-up: UART or USB (USB on LPC134x only).

On LPC134x: USB MSC and HID on-chip drivers.

Serial interfaces:

USB 2.0 full-speed device controller with on-chip PHY for device (LPC1342/43 only).

UART with fractional baud rate generation, modem, internal FIFO, and RS-485/EIA-485 support.

SSP controller with FIFO and multi-protocol capabilities.

I2C-bus interface supporting full I2C-bus specification and Fast-mode Plus with a data rate of 1 Mbit/s with multiple address recognition and monitor mode.

Other peripherals:

Up to 42 General Purpose I/O (GPIO) pins with configurable pull-up/pull-down resistors.

Four general purpose counter/timers with a total of four capture inputs and 13 match outputs.

Programmable WatchDog Timer (WDT).

System tick timer.

Serial Wire Debug and Serial Wire Trace port.

High-current output driver (20 mA) on one pin.

High-current sink drivers (20 mA) on two I2C-bus pins in Fast-mode Plus.

Integrated PMU (Power Management Unit) to minimize power consumption during Sleep, Deep-sleep, and Deep power-down modes.

Three reduced power modes: Sleep, Deep-sleep, and Deep power-down.

Single power supply (2.0 V to 3.6 V).

10-bit ADC with input multiplexing among 8 pins.

GPIO pins can be used as edge and level sensitive interrupt sources.

Clock output function with divider that can reflect the system oscillator clock, IRC clock, CPU clock, or the watchdog clock.

Processor wake-up from Deep-sleep mode via a dedicated start logic using up to 40 of the functional pins.

Brownout detect with four separate thresholds for interrupt and one threshold for forced reset.

Power-On Reset (POR).

Integrated oscillator with an operating range of 1 MHz to 25 MHz.

12 MHz internal RC oscillator trimmed to 1 % accuracy over the entire temperature and voltage range that can optionally be used as a system clock.

Programmable watchdog oscillator with a frequency range of 7.8 kHz to 1.8 MHz.

System PLL allows CPU operation up to the maximum CPU rate without the need for a high-frequency crystal. May be run from the system oscillator or the internal RC oscillator.

For USB (LPC1342/43), a second, dedicated PLL is provided.

Code Read Protection (CRP) with different security levels.

Unique device serial number for identification.

Available as 48-pin LQFP package and 33-pin HVQFN package.

LPC1311/13/42/43應(yīng)用：

eMetering

Lighting

Alarm systems

White goods


圖1。LPC1311/13/42/43方框圖

圖2。LPC1311/13/42/43時(shí)鐘發(fā)生方框圖

圖3。LPC1311/13/42/43自供電USB接口框圖

圖3。LPC1342/43總線供電USB接口框圖