*** Using Compiler 'V5.06 update 5 (build 528)', folder: 'E:KEIL5install filesARMARMCCBin'
Build target 'Target 1'
compiling stm32f4xx_flash_ramfunc.c...
..FWLIBsrcstm32f4xx_flash_ramfunc.c(110): error:  #20: identifier "PWR_CR_FISSR" is undefined

LEAR_BIT(PWR->CR, PWR_CR_FISSR);
..FWLIBsrcstm32f4xx_flash_ramfunc.c(115): error:  #20: identifier "PWR_CR_FISSR" is undefined

ET_BIT(PWR->CR, PWR_CR_FISSR);
..FWLIBsrcstm32f4xx_flash_ramfunc.c(133): error:  #20: identifier "PWR_CR_FMSSR" is undefined

ET_BIT(PWR->CR, PWR_CR_FMSSR);
..FWLIBsrcstm32f4xx_flash_ramfunc.c(138): error:  #20: identifier "PWR_CR_FMSSR" is undefined

LEAR_BIT(PWR->CR, PWR_CR_FMSSR);
..FWLIBsrcstm32f4xx_flash_ramfunc.c: 0 warnings, 4 errors
compiling usart.c...
..SYSTEMusartusart.c(47): error:  #260-D: explicit type is missing ("int" assumed)
  _sys_exit(int x)
..SYSTEMusartusart.c: 0 warnings, 1 error
compiling stm32f4xx_rcc.c...
..FWLIBsrcstm32f4xx_rcc.c(2106): error:  #20: identifier "RCC_BDCR_LSEMOD" is undefined

ET_BIT(RCC->BDCR, RCC_BDCR_LSEMOD);
..FWLIBsrcstm32f4xx_rcc.c(2110): error:  #20: identifier "RCC_BDCR_LSEMOD" is undefined

LEAR_BIT(RCC->BDCR, RCC_BDCR_LSEMOD);
..FWLIBsrcstm32f4xx_rcc.c: 0 warnings, 2 errors
".Objectsmo.axf" - 7 Error(s), 0 Warning(s).
Target not created.
Build Time Elapsed:  00:00:04