Stm32F407 Clock Configuration Issue

Hi,

I am working on my Stm32F407 Discovery Board. I use CMSIS when I codding and I have some problems with PLLCFGR register. I want to using 168 mhz clock speed. This is my Clock Configuration code and I get problem in PLLM configuration in PLLCFGR register. PLLM value does not change. I want to set 8 but it still 19.

And we come to the most interesting part. I was try my clock configuration in Cubemx. Then I run Cubemx's code and it works! All register value is as I want. I save ALL CLOCK register values from Atollic's SFR page and write to registers with CMSIS code. But I still get wrong PLLCFGR value. This clock configuration working on CubeMx but doesnt work on CMSIS!! I dont understand it.

 RCC-> CFGR		|= 0x4008940A;
	RCC-> PLLCFGR 	 = 0x00000000;
 RCC-> PLLCFGR	 = 0x00000008;			//PLLM 8
	RCC-> PLLCFGR	|= 0x00400000;			//PLL Source is HSE
	RCC-> PLLCFGR 	|= 0x00005400;			//PLLN 336
	RCC-> PLLCFGR	|= 0x04000000;			//PLLQ 4
	RCC-> PLLI2SCFGR|= 0x50003C00;
	RCC-> CR		|= 0x00010000;			//HSE On
	RCC-> CR		|= 0x01000000;			//PLL On
	RCC-> CR		|= 0x04000000;			//PLLI2S On
 
	RCC-> AHB1ENR	|= 0x00000080;			//GPIOH Clock Enable For HSE Crystal
 
	RCC-> AHB1ENR 	|= 0x00040000;			//Backup SRAM Clock Enable
 
	RCC-> APB1ENR |= 0x10000000;			//Power Interface Clock Enable
 
	PWR-> CR		|= 0x0100;				//Backup Access Enable
 
	RCC-> APB2ENR	|= 0x00004000;			//System Configuration Controller Enable