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2005-12-26 by Gus
What would be the closest crystal to 70 Mhz while keeping the standard UART baud rates? It would be nice if it would work with x6 pll multiplier so we an stop the pll to go in lower power mode Gus
2005-12-26 by Paul Curtis
Gus, The PC210x has the fractional division register so I think you'll find there are a number of crystals that are candidates. -- Paul.
> -----Original Message----- > From: Gus [mailto:gus_is_working@...] > Sent: 26 December 2005 18:30 > To: lpc2000@yahoogroups.com > Subject: [lpc2000] The right crystal for 70Mhz LPC2103 > > > What would be the closest crystal to 70 Mhz while keeping the > standard UART baud rates? > > It would be nice if it would work with x6 pll multiplier so we an > stop the pll to go in lower power mode > > Gus > > > > > > > ------------------------ Yahoo! Groups Sponsor > --------------------~--> > Most low income homes are not online. Make a difference this > holiday season! > http://us.click.yahoo.com/5UeCyC/BWHMAA/TtwFAA/dN_tlB/TM > -------------------------------------------------------------- > ------~-> > > > Yahoo! Groups Links > > > > > > > >
2005-12-26 by lpc2100_fan
Gus, the LPC2103 has a fractional BR-Generator. So you could e.g. take 10 MHz and multiply it with 7 and still get 115200 Baud fairly excactly. If I remember it right, the actual bausrate difference is less than 1% Bob --- In lpc2000@yahoogroups.com, "Gus" <gus_is_working@y...> wrote:
> > What would be the closest crystal to 70 Mhz while keeping the > standard UART baud rates? > > It would be nice if it would work with x6 pll multiplier so we an > stop the pll to go in lower power mode > > Gus >
2005-12-26 by Karl Olsen
---- Original Message ----
From: "Gus" <gus_is_working@...> To: <lpc2000@yahoogroups.com> Sent: Monday, December 26, 2005 7:30 PM Subject: [lpc2000] The right crystal for 70Mhz LPC2103 > What would be the closest crystal to 70 Mhz while keeping the > standard UART baud rates? > > It would be nice if it would work with x6 pll multiplier so we an > stop the pll to go in lower power mode The LPC2101/02/03 have the fractional baudrate generator, so you can get almost any baudrates with any crystal. 10 MHz lets you hit 70 MHz exactly, and pclk = 70 MHz also gets almost exact baud rates without the fractional divider. 10 MHz only lets you do ISP with 38400 bps, but it is less important with the limited amount of flash to program. Karl Olsen
2005-12-26 by Joel Winarske
> What would be the closest crystal to 70 Mhz while keeping the > standard UART baud rates? > > It would be nice if it would work with x6 pll multiplier so we an > stop the pll to go in lowe Hi Gus, I posted this tool a while back, it's used to determine the optimal fractional divider values for any given PCLK and baud rate. It applies to all LPC devices with fractional divider enabled UARTs, which are currently the LPC214x and the LPC2101/LPC2101/LPC2103. http://groups.yahoo.com/group/lpc2000/files/Tools/lpc2fdcalc.exe Joel