Freescale Semiconductor ColdFire MCF5211, Reference Manual

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Pulse-Width Modulation (PWM) Module
MCF5213 ColdFire® Integrated Microcontroller Reference Manual, Rev. 3
24-2 Freescale Semiconductor
Main features include the following:
• Double-buffered period and duty cycle
• Left- or center-aligned outputs
• Eight independent PWM modules. Notice that only the four odd PWM channel outputs are
available on the device. The even channels can be used for concatenation purposes to generate
16-bit PWM for the odd channels.
• Byte-wide registers provide programmable duty cycle and period control
• Four programmable clock sources
NOTE
The GPIO module must be configured to enable the peripheral function of
the appropriate pins (refer to
” ) prior to configuring the PWM module.
24.2 Memory Map/Register Definition
This section describes the registers and control bits in the PWM module. There are eight independent
PWM modules, each with its own control and counter registers, although only four channels have an
output signal. The memory map for the PWM is shown below.
Table 24-1. PWM Memory Map
IPSBAR Offset
1,2
1
Addresses not assigned to a register and undefined register bits are reserved for expansion. Write accesses to these
reserved address spaces and reserved register bits have no effect.
2
A 32-bit access to any of these registers results in a bus transfer error.
Register
Width
(bits)
Access Reset Value Section/Page
0x1B_0000 PWM Enable Register (PWME) 8 R/W 0x00 24.2.1/24-3
0x1B_0001 PWM Polarity Register (PWMPOL) 8 R/W 0x00 24.2.2/24-3
0x1B_0002 PWM Clock Select Register (PWMCLK) 8 R/W 0x00 24.2.3/24-4
0x1B_0003 PWM Prescale Clock Select Register (PWMPRCLK) 8 R/W 0x00 24.2.4/24-5
0x1B_0004 PWM Center Align Enable Register (PWMCAE) 8 R/W 0x00 24.2.5/24-6
0x1B_0005 PWM Control Register (PWMCTL) 8 R/W 0x00 24.2.6/24-6
0x1B_0008 PWM Scale A Register (PWMSCLA) 8 R/W 0x00 24.2.7/24-7
0x1B_0009 PWM Scale B Register (PWMSCLB) 8 R/W 0x00 24.2.8/24-8
0x1 n
n = 0–7
PWM Channel n Counter Register (PWMCNT n ) 8 R/W 0x00 24.2.9/24-9
0x1 n
n = 0–7
PWM Channel n Period Register (PWMPER n ) 8 R/W 0xFF 24.2.10/24-10
0x1 n
n = 0–7
PWM Channel n Duty Register (PWMDTY n ) 8 R/W 0xFF 24.2.11/24-10
0x1B_0024 PWM Shutdown Register (PWMSDN) 8 R/W 0x00 24.2.12/24-11