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Sender: "piclist-bounces@mit.edu" Date: Tue, 20 Oct 2020 07:42:24 -0700 Subject: [PIC] Crystal frequency selection Thread-Topic: [PIC] Crystal frequency selection Thread-Index: Adam8K1K8zJAnQd6Q1SFxZwKIh+pRA== Message-ID: <5F8EF750.1010301@narwani.org> List-Help: List-Subscribe: , List-Unsubscribe: , Reply-To: Microcontroller discussion list - Public. Accept-Language: en-US X-MS-Exchange-Organization-AuthAs: Anonymous X-MS-Exchange-Organization-AuthSource: TS500.efplus4.local X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-Exchange-Organization-SenderIdResult: Pass X-MS-Exchange-Organization-PRD: mit.edu X-MS-TNEF-Correlator: received-spf: None (protection.outlook.com: narwani.org does not designate permitted sender hosts) dkim-signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=narwani.org ; s=default; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Date: Message-ID:Subject:From:To:Reply-To:Sender:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=Ouhfc/TA5KpmRFTbJ9Z0Vabh8gdlzFif6gs1Usvo02w=; b=r/0BaN4Usbw0vuEUYzeiZ+24jG rW4bIdVqwNRGEHYdpmZUIbp5B7d83sElPwWnl0VJXF6n4mD3uTrF0gjaBWI0uyt+QHlio4b1XIgQV XeUUfOa9K/9Khiv6QkGjjw5qRB8CrD2JkmB7g1f/2jriEDPxleiQ7xdnPZTbWYgMroWAI2+2W29n/ cqqchvbIDUGP1DM53cs29yjaoE9yO+3ZMiIBSxnY2FZJTNJVAI06gIX6Dp0CU9QFSqfBlBaLsNjAT r3UpTT06nxuNSvUh2VTpbNFRLZjWXykFLGWtrRgYVOmE0EPAtprCuww+0qHs84VNA+bp3h4b3OKnG G80ehECA==; authentication-results: spf=none (sender IP is 68.65.123.241) smtp.mailfrom=narwani.org; mit.edu; dkim=pass (signature was verified) header.d=narwani.org;mit.edu; dmarc=bestguesspass action=none header.from=narwani.org; user-agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 errors-to: piclist-bounces@mit.edu list-id: "Microcontroller discussion list - Public." list-post: x-beenthere: piclist@mit.edu x-mailman-version: 2.1.6 x-source-args: x-source-dir: x-antiabuse: Sender Address Domain - narwani.org x-source: x-authenticated-sender: premium47.web-hosting.com: ca4@narwani.org x-topics: [PIC] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 A bit academic, but this is bugging me... I was trying to get as close=20 to 115,200 baud on a PIC18F running at 64Mhz (or thereabouts). At 64Mhz, best I can get is 0.8% error using SPBRG=3D34. Calculating backwards, to get exactly 115,200, I can't find an "exact"=20 crystal. Shouldn't I be able to find one of those "odd" values to get exactly=20 115,200 baud at around 64Mhz? Cheers, -Neil. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .