Wow nextpnr's ECP5 PLL calculator is just wizardry.
"Please make me a 25.175MHz clock from this 25MHz input clock"
"Easy: first, divide that input by 8 for a 3.125MHz reference. Feed that into the VCO with a 145x feedback multiplier, for a 453.125MHz frequency reference. Finally, stick an 18x divider on the VCO, and there you go: 25.1736MHz, 55ppm off from what you wanted."
🤯
Dave Anderson
npub1mt…xwant
2024-08-13 03:27:35 UTC
Author Public Key
npub1mtg38agwglttl7melxnfqphlm95uymnrdedw62h9j7cyquynza0szxwantSeen on
wss://relay.momostr.pinkPublished at
2024-08-13 03:27:35 UTCEvent JSON
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"content": "Wow nextpnr's ECP5 PLL calculator is just wizardry.\n\n\"Please make me a 25.175MHz clock from this 25MHz input clock\"\n\n\"Easy: first, divide that input by 8 for a 3.125MHz reference. Feed that into the VCO with a 145x feedback multiplier, for a 453.125MHz frequency reference. Finally, stick an 18x divider on the VCO, and there you go: 25.1736MHz, 55ppm off from what you wanted.\"\n\n🤯",
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