- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I need to using an external crystal for better performance (40MHz TCXO).
So I connect this with P5(1).
Configure all the clock using external clock.
But the system can't boot up.
Any special setting needed?
Please check the attached for clock setting.
BTW: The crystal is 40MHz. Is this must be 48MHz/24MHz?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
P5_1 is for input of an external oscillator, not only a crystal. I think this is just a naming difference, is it?
When you did not additionally provide the 24MHz crystal your system will not run in this configuration.
What is the exact device number you're using?
Bob
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
CY8C4247LQ-BL483 and CY8C4248LQ-BL583
There 24MHz onboard, and running well using this 24MHz.
Yes, it is a TCXO with VDD 1ppm oscillator.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I would try to boot using IMO and then switch to external clock with CySysClkWriteHfclkDirect() API (see "System Reference Guide")
Bob
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Thanks, after using this method it works.
And in the system reference guide, it said PSOC4 can't boot with external clk, I just didn't notice this.