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LPC43 user manual PLL0AUDIO fractional: what is "L"?

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by svenb on Thu Jul 02 07:33:40 MST 2015
Hi!

The user manual for the LPC43xx parts (UM10503) states in section 12.7.5 "Fractional divider for PLL0AUDIO":


Quote:
When the fractional divider is active, the sigma-delta modulator block generates divider
values M and M+1 in the correct proportion so that an average division ratio of M+K/L is
realized where 0<=K<=L and M, K, and L are integer values. M Is determined by the
integer part of the PLLFRACT_CTRL register (PLLFRACT[21:15]) and K is determined by
the fractional part of the PLLFRACT_CTRL register (PLLFRACT[14:0]). Consecutive M
and M+1 values are then further encoded into appropriate MENC values before being
presented as input to the M-divider.



But what is L? One might assume that it is 2^14, but apparently that's not it. Am I overlooking something obvious or is that just not mentioned anywhere?

Thanks and best regards,
Sven

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