Content originally posted in LPCWare by Harukana on Wed Apr 10 06:13:34 MST 2013
Quote: guillaumeL
Hi,
I'm developing an application using I2C interface of the LPC1769. All is working fine but it seems the I2C SCL frequency is not accurate. For example, when I want this frequency at 100kHz it is OK but if I set 400kHz the frequency is only 350 kHz.
I use the PLL0 with Main oscillator @ 12MHz as input. The setting of the PLL is LPC_SC->PLL0CFG = 0x10018; (N= 2 & M = 25). Fcco is 300 MHz and I set LPC_SC->CCLKCFG = 0x02; to get 100MHz as system clock.
I2C clk is equal to system clock.
Do you know where this frequency "error" can come from?
Regards,
dear guillaumeL, I am dealing with i2c at the moment and find it very hard to figure out some functions. Could you please offer some help as you are experienced in I2c? thanks very much