HC32F4A0 系列用户手册 Rev1.01 Page 4 of 1808
4.2.1 系统框图 ............................................................................................................................... 98
4.2.2 时钟频率测量框图 ............................................................................................................... 99
4.3 时钟源规格........................................................................................................................................ 100
4.4 工作时钟规格 .................................................................................................................................... 102
4.5 晶振电路............................................................................................................................................ 105
4.5.1 外部高速振荡器 ................................................................................................................. 105
4.5.1.1 振荡器模式 ..................................................................................................................... 105
4.5.1.2 时钟输入模式.................................................................................................................. 106
4.5.2 外部高速振荡器故障检测 ................................................................................................. 107
4.5.2.1 检测到 XTAL 故障检测动作 ......................................................................................... 108
4.5.2.2 检测到 XTAL 振荡故障产生中断复位 ......................................................................... 109
4.5.3 外部低速振荡器 .................................................................................................................. 110
4.6 内部 RC 时钟 .................................................................................................................................... 111
4.6.1 HRC 时钟 ............................................................................................................................. 111
4.6.2 MRC 时钟 ............................................................................................................................ 111
4.6.3 LRC 时钟 ............................................................................................................................. 112
4.6.4 SWDTLRC 时钟 .................................................................................................................. 112
4.6.5 RTCLRC 时钟 ...................................................................................................................... 112
4.7 PLL 时钟 ........................................................................................................................................... 113
4.8 时钟切换步骤 .................................................................................................................................... 113
4.8.1 时钟源切换 .......................................................................................................................... 114
4.8.2 时钟分频切换 ...................................................................................................................... 115
4.9 时钟输出功能 .................................................................................................................................... 116
4.10 时钟频率测量 .................................................................................................................................... 117
4.10.1 时钟频率测量 ...................................................................................................................... 117
4.10.2 数字滤波功能 ...................................................................................................................... 118
4.10.3 中断/复位功能 ..................................................................................................................... 118
4.11 寄存器说明 ....................................................................................................................................... 119
4.11.1 CMU XTAL 配置寄存器器(CMU_XTALCFGR) ............................................................. 121
4.11.2 CMU XTAL 配置寄存器器(CMU_XTALSTBCR) ........................................................... 122
4.11.3 CMU XTAL 控制寄存器(CMU_XTALCR) ...................................................................... 123
4.11.4 CMU XTAL 振荡故障控制寄存器(CMU_XTALSTDCR) ............................................... 124
4.11.5 CMU XTAL 振荡故障状态寄存器(CMU_XTALSTDSR) ............................................... 125
4.11.6 CMU XTAL32 配置寄存器器(CMU_XTAL32CFGR) ..................................................... 125
4.11.7 CMU XTAL32 滤波寄存器(CMU_XTAL32NFR) ............................................................ 126
4.11.8 CMU XTAL32 控制寄存器(CMU_XTAL32CR) .............................................................. 126
4.11.9 CMU HRC 校准寄存器(CMU_HRCTRM) ....................................................................... 127
4.11.10 CMU HRC 控制寄存器(CMU_HRCCR)........................................................................... 128
4.11.11 CMU MRC 校准寄存器(CMU_MRCTRM) ...................................................................... 129
4.11.12 CMU MRC 控制寄存器(CMU_MRCCR) ......................................................................... 130
4.11.13 CMU LRC 校准寄存器(CMU_LRCTRM) ........................................................................ 131
4.11.14 CMU LRC 控制寄存器(CMU_LRCCR) ........................................................................... 132