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Groups > comp.arch.embedded > #27682
| Subject | Re: SPI Flash: don't work high-speed read at 48MHz |
|---|---|
| Newsgroups | comp.arch.embedded |
| References | <p7p1qc$f37$1@dont-email.me> <p7qr52$qn7$1@dont-email.me> |
| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
| Date | 2018-03-08 11:18 -0500 |
| Message-ID | <y_ydnSyTSYfE_zzHnZ2dnUU7-RmdnZ2d@supernews.com> (permalink) |
On 03/08/2018 03:10 AM, pozz wrote: > Il 07/03/2018 16:51, pozz ha scritto: >> I'm using Microchip SST26VF064B SPI Flash memory with an LPC1768 from >> LPC. >> >> It works until I change the SPI clock frequency from 24MHz to 48MHz. >> >> I'm using HIGH-SPEED READ command that should work up to 104MHz (the >> power supply is 3.3V). >> >> For example I read 0x28 0x26 when they should be 0x51 0x4C. >> >> 0010 1000 0010 0110 -> 0x28 0x26 >> 0101 0001 0100 1100 -> 0x51 0x4C >> >> They appears shifted by one bit... except the MSBit of the second byte. >> >> What do you think? > > It seems SSP peripheral of LPC1768 MCUs (the peripheral I'm using) has > an upper limit of 33MBit/s. I see this limit in the datasheet. > So switch to the wrong clock edge. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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SPI Flash: don't work high-speed read at 48MHz pozz <pozzugno@gmail.com> - 2018-03-07 16:51 +0100
Re: SPI Flash: don't work high-speed read at 48MHz David Brown <david.brown@hesbynett.no> - 2018-03-07 17:46 +0100
Re: SPI Flash: don't work high-speed read at 48MHz Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-03-07 11:48 -0500
Re: SPI Flash: don't work high-speed read at 48MHz pozz <pozzugno@gmail.com> - 2018-03-08 09:10 +0100
Re: SPI Flash: don't work high-speed read at 48MHz Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-03-08 11:18 -0500
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