Datasheet
UM10398 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
User manual Rev. 12.3 — 10 June 2014 376 of 547
21.1 How to read this chapter
The 32-bit timer blocks are identical for all LPC1100XL parts.
Compared to the timer block for the LPC1100/LPC1100L/LPC1100C series, the following
features have been added:
• One additional capture input for each timer.
• Capture-clear function for easy pulse-width measurement (see Section 21.7.11).
21.2 Basic configuration
The CT32B0/1 are configured using the following registers:
1. Pins: The CT32B0/1 pins must be configured in the IOCONFIG register block
(Section 7.4
).
2. Power and peripheral clock: In the SYSAHBCLKCTRL register, set bit 9 and bit 10
(Table 21
). The peripheral clock (PCLK) is provided by the system clock (see
Table 20
).
21.3 Features
• Two 32-bit counter/timers with a programmable 32-bit prescaler.
• Counter or Timer operation.
• The timer and prescaler may be configured to be cleared on a designated capture
event. This feature permits easy pulse-width measurement by clearing the timer on
the leading edge of an input pulse and capturing the timer value on the trailing edge.
• Two 32-bit capture channels that can take a snapshot of the timer value when an input
signal transitions. A capture event may also optionally generate an interrupt.
• Four 32-bit match registers that allow:
– Continuous operation with optional interrupt generation on match.
– Stop timer on match with optional interrupt generation.
– Reset timer on match with optional interrupt generation.
• Up to four external outputs corresponding to match registers with the following
capabilities:
– Set LOW on match.
– Set HIGH on match.
– Toggle on match.
– Do nothing on match.
• For each timer, up to four match registers can be configured as PWM allowing to use
up to three match outputs as single edge controlled PWM outputs.
UM10398
Chapter 21: LPC1100XL series: 32-bit counter/timer CT32B0/1
Rev. 12.3 — 10 June 2014 User manual