What conditions will prescaler be cleared by event(SCT Timer)?

wilsonchenwk — Wed, 10 Jul 2019 06:53:33 GMT

According to UM10736:

15.7.7 Clearing the prescaler
When enabled by a non-zero PRE field in the Control register, the prescaler acts as a
clock divider for the counter, like a fractional part of the counter value. The prescaler is
cleared whenever the counter is cleared or loaded for any of the following reasons:
• Hardware reset
• Software writing to the counter register
• Software writing a 1 to the CLRCTR bit in the control register
• an event selected by a 1 in the counter limit register when BIDIR = 0
When BIDIR is 0, a limit event caused by an I/O signal can clear a non-zero prescaler.
However, a limit event caused by a Match only clears a non-zero prescaler in one special
case as described Section 15.7.8

When BIDIR is 0,there are only two conditions of event that clear a non-zero prescaler . Is it right?

1.A limit event caused by an I/O signal can clear a non-zero prescaler.

2. A Match only clears a non-zero prescaler in one special case as described Section 15.7.8,

I don't understand what 15.7.8 describe about the special case,and I don't want prescaler be cleared in my design.

Thanks.

Re: What conditions will prescaler be cleared by event(SCT Timer)?

soledad — Wed, 17 Jul 2019 15:27:57 GMT

Hello,

When BIDIR is 0,there are only two conditions of event that clear a non-zero prescaler . Is it right?

Yes

Please check the appliction note AN11538, this application note is a collection of examples and usage notes for the
SCTimer/PWM block used in NXP microcontrollers. This may helps.

Have a great day,
Sol

-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!

- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------

topic What conditions will prescaler be cleared by event(SCT Timer)? in LPC Microcontrollers

What conditions will prescaler be cleared by event(SCT Timer)?

Re: What conditions will prescaler be cleared by event(SCT Timer)?