QE128 Quick Reference User Guide, Rev. 1.0
Freescale Semiconductor
12-1
Chapter 12
Generating PWM Signals Using Timer/Pulse-Width
Modulator (TPM) Module for the QE Microcontrollers
12.1
Overview
This is a quick reference for enabling the pulse width modulator (PWM) functionality of the
timer/pulse-width modulator (TPM) module for the QE family microcontrollers (MCUs). Basic
information about the functional description and configuration options are provided. The following
example may be modified to suit an application. The PWM project is made for the MC9S08QE128 and
MCF51QE128 MCUs.
TPM Quick Reference
Because there is more than one TPM modules on QE MCU, there are three full sets of registers. In
the register names below, where there’s a small x, there would be a 1, 2 or 3 in your software to
distinguish the registers that are on TPM1 from those on TPM2 or from TPM3. A small n in a
register name below is a place-holder for the channel number
Module configuration::
TPMxSC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
TOF – Timer Overflow Flag
CLKS[B:A] – Clock Source Select
TOIE – Timer Overflow Interrupt Enable
PS[2:0] – Prescale Divisor Select
CPWMS – Center-Aligned PWM Select
TPMxCNTH
Bit 15
14
13
12
11
10
9
Bit 8
TPMxCNTL
Bit 7
6
5
4
3
2
1
Bit 0
Any write to TPMxCNTH or TPMxCNTL clears the 16-bit counter
TPMxMODH
Bit 15
14
13
12
11
10
9
Bit 8
TPMxMODL
Bit 7
6
5
4
3
2
1
Bit 0
Modulo value for TPWM module
TPMxCnSC
CHnF
CHnIE
MSnB
MSnA
ELSnB
ELSnA
CHnF – Channel n Flag
MSnA – Mode Select A for TPM Channel n
CHnIE – Channel n Interrupt Enable
ELSn[[B:A] – Edge/Level Select Bits
MSnB – Mode Select B for TPM Channel n
TPMxCnVH
Bit 15
14
13
12
11
10
9
Bit 8
TPMxCnVL
Bit 7
6
5
4
3
2
1
Bit 0
Captured TPM counter of input capture function OR output copare value for output compare of PWM function
