Philips Semiconductors

LPC2104/2105/2106

Single-chip 32-bit microcontrollers

Product data

Rev. 04 — 05 February 2004

18 of 32

9397 750 12792

© Koninklijke Philips Electronics N.V. 2004. All rights reserved.

6.14.1

Features

be disabled.

6.15 Real time clock

The Real Time Clock (RTC) is designed to provide a set of counters to measure time

when normal or idle operating mode is selected. The RTC has been designed to use

little power, making it suitable for battery powered systems where the CPU is not

running continuously (Idle mode).

6.15.1

Features

Day of Year.

various crystal frequencies.

6.16 Pulse width modulator

The PWM is based on the standard Timer block and inherits all of its features,

although only the PWM function is pinned out on the LPC2104, LPC2105 and

LPC2106. The Timer is designed to count cycles of the peripheral clock (PCLK) and

optionally generate interrupts or perform other actions when specified timer values

occur, based on seven match registers. It also includes four capture inputs to save the

timer value when an input signal transitions, and optionally generate an interrupt

when those events occur. The PWM function is in addition to these features, and is

based on match register events.

The ability to separately control rising and falling edge locations allows the PWM to

be used for more applications. For instance, multi-phase motor control typically

requires three non-overlapping PWM outputs with individual control of all three pulse

widths and positions.

Two match registers can be used to provide a single edge controlled PWM output.

One match register (MR0) controls the PWM cycle rate, by resetting the count upon

match. The other match register controls the PWM edge position. Additional single