Freescale Semiconductor
19-1
PXR40 Microcontroller Reference Manual, Rev. 1
Chapter 19
System Timer Module (STM)
19.1
Introduction
19.1.1
Overview
The System Timer Module (STM) is a 32-bit timer designed to support commonly required system and
application software timing functions. The STM includes a 32-bit up counter and four 32-bit compare
channels with a separate interrupt source for each channel. The counter is driven by the system clock
divided by an 8-bit prescale value (1 to 256).
19.1.2
Features
The STM has the following features:
•
One 32-bit up counter with 8-bit prescaler
•
Four 32-bit compare channels
— One channel with a dedicated interrupt node
— Three channels sharing the same interrupt node
•
Independent interrupt source for each channel
•
Counter can be stopped in debug mode
19.1.3
Modes of Operation
The STM supports two device modes of operation: normal and debug. When the STM is enabled in normal
mode, its counter runs continuously. In debug mode, operation of the counter is controlled by the FRZ bit
in the STM_CR register. If the FRZ bit is set, the counter is stopped in debug mode, otherwise it continues
to run.
19.2
External Signal Description
The STM does not have any external interface signals.
19.3
Memory Map and Register Definition
The STM programming model has fourteen 32-bit registers. The STM registers can only be accessed using
32-bit (word) accesses. Attempted references using a different size or to a reserved address generates a bus
error termination.
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Page 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...