[U-Boot-Users] i.MX31: question about CFG_HZ and CKIL

Jens Gehrlein sew_s at tqs.de
Wed May 7 10:59:31 CEST 2008


Hi all,

in the i.MX31 processor reference manual they mention a 32 kHz clock as 
input for several timers and controllers. Sometimes it's called 
ipg_clk_32k. But the documentation does not clearly state, that this 
clock actually is the CKIL.

As far as I could derive from the ADS schematics the CKIL is feeded with 
32768 Hz instead of 32000 Hz. On our board we use 32768 Hz either.

If CKIL is the above mentioned 32 kHz clock, the resulting deviation in 
the timers is "only" about 2.4% as long as CFG_HZ in mx31ads.h is 32000 
Hz. Although it works with the current definition, I'd like to know your 
opinions, whether it is necessary to adjust this value.

Thank you for comments.

Best Regards,
Jens




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