10 pwm channel period registers (pwmpern), 10pwm channel period registers (pwmper n, 10 pwm channel period registers (pwmper n ) – Freescale Semiconductor ColdFire MCF52210 User Manual

Page 484

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Pulse-Width Modulation (PWM) Module

MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2

27-10

Freescale Semiconductor

(PWMEn=0), the PWMCNTn register does not count. When a channel is enabled (PWMEn=1), the
associated PWM counter starts at the count in the PWMCNTn register. For more detailed information on
the operation of the counters, refer to

Section 27.3.2.4, “PWM Timer Counters.”

27.2.10 PWM Channel Period Registers (PWMPERn)

The PWM period registers determine the period of the associated PWM channel. Refer to

Section 27.3.2.3,

“PWM Period and Duty”

for more information.

Calculating the output period depends on the output mode (center-aligned has twice the period as
left-aligned mode) as well as PWMPERn. See the below equation:

Eqn. 27-3

For boundary case programming values (e.g. PWMPERn = 0x00), please refer to

Section 27.3.2.8, “PWM

Boundary Cases”

.

IPSBAR

Offset:

0x1B_000C (PWMCNT0)
0x1B_000D (PWMCNT1)
0x1B_000E (PWMCNT2)
0x1B_000F (PWMCNT3)
0x1B_0010 (PWMCNT4)
0x1B_0011 (PWMCNT5)
0x1B_0012 (PWMCNT6)
0x1B_0013 (PWMCNT7)

Access: User Read/Write

7

6

5

4

3

2

1

0

R

COUNT

W

Reset:

0

0

0

0

0

0

0

0

Figure 27-10. PWM Counter Registers (PWMCNTn)

Table 27-10. PWMCNTn Field Descriptions

Field

Description

7–0

COUNT

Current value of the PWM up counter. Resets to zero when written.

PWMn period

Channel clock period

PWMCAE CAEn

[

] 1

+

(

) PWMPERn

Ч

Ч

=

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