Introduction - NXP Semiconductors MC9S08SU16 Reference Manual

Introduction

20.2 Introduction
20.2.1 Features
The pulse width timer (PWT) includes the following features:
• Automatic measurement of pulse width with 16 bit resolution
• Separate positive and negative pulse width measurements
• Programmable measuring time between successive alternating edges, rising edges or
falling edges
• Programmable pre-scaler from clock input as 16-bit counter time base
• Two selectable clock sources — bus clock and alternative clock
• Four selectable pulse inputs
• Programmable interrupt generation upon pulse width value updated and counter
overflows
20.2.2 Modes of operation
This module supports the following mode:
• Run Mode
When enabled, the pulse width timer module is active.
• Wait Mode
When enabled, the pulse width timer module is active and can perform the waking up
function if the corresponding interrupt is enabled.
• Stop Mode
The pulse width timer module is halted when entering stop and the register contents
and operating status is preserved. If stop exits with reset then the module resets. If
stop exits with another source, the module resumes operation based on module status
upon exit.
• Active Background Mode
Upon entering BDM mode, the PWT suspends all counting and pulse edge detection
until the microcontroller returns to normal user operating mode. Counting and edge
detection resume from the suspended value when normal user operating mode returns
as long as the PWTSR bit (PWT software reset) is not written to 1 and the PWT
module is still enabled.
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MC9S08SU16 Reference Manual, Rev. 5, 4/2017
NXP Semiconductors