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Clock control (CLK) RM0016

84/449 Doc ID 14587 Rev 8

Figure 22. Clock switching flowchart (automatic mode example)

Reset

MCU in Run mode with HSI/8

Write target clock source in CLK_SWR

Target clock source ready after

CLK_SWR

CLK_CMSR

SWBSY

Set SWEN bit in CLK_SWCR

Target clock source powered on

SWBSY

stabilization time

Switch busy

MCU in Run mode

with new master clock source

SOFTWARE ACTIONHARDWARE ACTION

Reset switch busy flag

Update clock master status

Clear SWIF flag

Set SWIEN bit in CLK_SWCR to enable interrupt if suitable

Interrupt if activated

SWIF

Switch done

Default Chapter2
- Table of Contents2
Central Processing Unit (CPU)23
- Introduction23
- CPU Registers23
- Global Configuration Register (CFG_GCR)27
Boot ROM29
Memory and Register Map30
- Memory Layout30
- Register Description Abbreviations33
- Table 4. List of Abbreviations33
Flash Program Memory and Data EEPROM34
- Introduction34
- Glossary34
- Main Flash Memory Features35
- Memory Organization36
- Memory Protection44
- Memory Programming46
- ICP and IAP49
- Table 5. Block Size49
- Table 6. Memory Access Versus Programming Method50
- Flash Registers51
Single Wire Interface Module (SWIM) and Debug Module (DM)57
- Introduction57
- Main Features57
- SWIM Modes57
- Figure 12. SWIM Pin Connection57
Interrupt Controller (ITC)58
- ITC Introduction58
- Interrupt Masking and Processing Flow58
- Interrupts and Low Power Modes62
- Activation Level/Low Power Mode Control62
- Concurrent and Nested Interrupt Management63
- External Interrupts65
- Interrupt Instructions65
- Table 11. Dedicated Interrupt Instruction Set65
- Figure 16. Nested Interrupt Management65
- Interrupt Mapping66
- ITC and EXTI Registers67
Power Supply72
- Figure 17. Power Supply Overview72
Reset (RST)73
- Reset State" and "Under Reset" Definitions73
- Reset Circuit Description73
- Figure 18. Reset Circuit73
- Internal Reset Sources74
- RST Register Description76
  - Reset Status Register (RST_SR)76
- RST Register Map76
- Table 13. RST Register Map76
Clock Control (CLK)77
- Figure 20. Clock Tree78
- Master Clock Sources79
- Master Clock Switching82
- Low Speed Clock Selection85
- CPU Clock Divider85
- Figure 23. Clock Switching Flowchart (Manual Mode Example)85
- Peripheral Clock Gating (PCG)86
- Clock Security System (CSS)87
- Clock-Out Capability (CCO)88
- CLK Interrupts88
- Table 16. CLK Interrupt Requests88
- CLK Register Description89
- CLK Register Map and Reset Values100
- Table 19. CLK Register Map and Reset Values100
Power Management101
- General Considerations101
  - Clock Management for Low Consumption102
- Low Power Modes102
- Additional Analog Power Controls104
  - Fast Flash Wakeup from Halt Mode104
  - Very Low Flash Consumption in Active-Halt Mode104
General Purpose I/O Ports (GPIO)105
- Introduction105
- GPIO Main Features105
- Port Configuration and Usage106
- Reset Configuration108
- Unused I/O Pins108
- Low Power Modes108
- Input Mode Details108
- Output Mode Details109
- GPIO Registers111
Auto-Wakeup (AWU)114
- Introduction114
- LSI Clock Measurement114
- Figure 25. AWU Block Diagram114
- AWU Functional Description115
- AWU Registers118
Beeper (BEEP)120
- Introduction120
- Beeper Functional Description120
- Beeper Registers121
Independent Watchdog (IWDG)122
- Introduction122
- IWDG Functional Description122
- Figure 27. Independent Watchdog (IWDG) Block Diagram122
- Table 28. Watchdog Timeout Period (LSI Clock Frequency = 128 Khz)123
- IWDG Registers124
Window Watchdog (WWDG)126
- Introduction126
- WWDG Main Features126
- WWDG Functional Description126
- Figure 28. Watchdog Block Diagram127
- How to Program the Watchdog Timeout128
- Figure 29. Approximate Timeout Duration128
- WWDG Low Power Modes129
- Table 30. Window Watchdog Timing Example129
- Table 31. Effect of Low Power Modes on WWDG129
- Figure 30. Window Watchdog Timing Diagram129
- Hardware Watchdog Option130
- Using Halt Mode with the WWDG (WWDGHALT Option)130
- WWDG Interrupts130
- WWDG Registers130
  - Control Register (WWDG_CR)130
  - Window Register (WWDG_WR)130
- Window Watchdog Register Map and Reset Values131
- Table 32. WWDG Register Map and Reset Values131
Timer Overview132
- Table 33. Timer Characteristics132
- Timer Feature Comparison133
- Glossary of Timer Signal Names133
- Table 34. Timer Feature Comparison133
- Table 35. Glossary of Internal Timer Signals134
- Figure 44: Control Circuit in Normal Mode, Fck_Psc = Fmaster134
- Table 36. Explanation of Indices'I', 'N', and 'X135
16-Bit Advanced Control Timer (TIM1)136
- Introduction136
- TIM1 Main Features137
- Figure 31. TIM1 General Block Diagram138
- Figure 32. Time Base Unit138
- TIM1 Time Base Unit139
- TIM1 Clock/Trigger Controller149
- TIM1 Capture/Compare Channels163
- TIM1 Interrupts184
- TIM1 Registers185
16-Bit General Purpose Timers (TIM2, TIM3, TIM5)216
- Introduction216
- TIM2/TIM3 Main Features216
- TIM5 Main Features217
- TIM2/TIM3/TIM5 Functional Description217
- TIM2/TIM3/TIM5 Interrupts221
- Figure 87. Output Stage221
- Figure 88. Output Stage of Channel 1221
- TIM2/TIM3/TIM5 Registers223
8-Bit Basic Timer (TIM4, TIM6)243
- Introduction243
- Figure 89. TIM4 Block Diagram243
- Figure 90. TIM6 Block Diagram243
- TIM4 Main Features244
- TIM6 Main Features244
- TIM4/TIM6 Interrupts244
- TIM4/TIM6 Clock Selection244
- TIM4/TIM6 Registers245
Serial Peripheral Interface (SPI)253
- Introduction253
- SPI Main Features253
- SPI Functional Description254
- SPI Registers271
- SPI Register Map and Reset Values277
- Table 47. SPI Register Map and Reset Values277
Inter-Integrated Circuit (I 2 C) Interface278
- Introduction278
- I 2 C Main Features278
- C General Description279
- Figure 100. I 2 C Bus Protocol279
- I 2 C Functional Description281
- I 2 C Low Power Modes291
- Table 48. I 2 C Interface Behavior in Low Power Modes291
- I 2 C Interrupts292
- Table 49. I 2 C Interrupt Requests292
- Figure 109. I2C Interrupt Mapping Diagram292
- I 2 C Registers293
Universal Asynchronous Receiver Transmitter (UART)307
- Introduction307
- Table 52. UART Configurations307
- UART Main Features308
- UART Functional Description309
- LIN Mode Functional Description333
- UART Low Power Modes346
- UART Interrupts346
- Table 59. UART Interface Behavior in Low Power Modes346
- Table 60. UART Interrupt Requests346
- Figure 138. UART Interrupt Mapping Diagram347
- UART Registers348
Controller Area Network (Becan)362
- Introduction362
- Becan Main Features362
- Becan General Description363
- Operating Modes365
- Test Modes367
- Functional Description368
- Interrupts383
- Figure 155. Event Flags and Interrupt Generation383
- Register Access Protection384
- Clock System384
- Becan Low Power Modes384
- Table 67. Becan Behavior in Low Power Modes384
- Becan Registers385
- CAN Register Map407
Analog/Digital Converter (ADC)411
- Introduction411
- ADC Main Features411
- ADC Extended Features411
- Figure 158. ADC1 Block Diagram412
- Figure 159. ADC2 Block Diagram413
- ADC Pins414
- ADC Functional Description414
- ADC Low Power Modes420
- ADC Interrupts420
- Table 72. Low Power Modes420
- Table 73. ADC Interrupts in Single and Non-Buffered Continuous Mode (ADC1 and ADC2)420
- Table 74. ADC Interrupts in Buffered Continuous Mode (ADC1)421
- Table 75. ADC Interrupts in Scan Mode (ADC1)422
- Data Alignment423
- Reading the Conversion Result423
- Figure 163. Right Alignment of Data423
- Figure 164. Left Alignment of Data423
- Schmitt Trigger Disable Registers424
- ADC Registers425

Brand	ST
Model	STM8S
Category	Microcontrollers
Language	English

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