Chapter 5 STM Arm Timer Programming 1 A

Chapter 5 STM Arm Timer Programming 1

A 3 -bit Counter 2

An 8 -bit up-counter stages 3

An 8 -bit down-counter stages 4

Counting Events Using a Counter 5

Using Counter as a Timer 6

Capturing 7

System Tick Timer Internal Structure 8

STCTRL (System Tick Control) 9

System Tick Counting 10

STRELOAD vs. STCURRENT 11

STMF 466 RE Arm timers 12

STM 32 F 4 xx Timer Prescale Options 13

RCC_APB 1 ENR Register is used to enable timer clock 14

RCC_APB 2 ENR Register is used to enable timer clock 15

Some of the STM 32 F 4 xx Timer Registers 16

CR 1 (Control 1) Register 17

Some of the CR 1 register bits 18

TIMx. SR Register 19

TIMx_SR (Staus) Register UIF Bit 20

TIMx counter (TIMx_CNT) 21

TIMx auto-reload register (TIMx_ARR) 22

TIM 2_CNT counter counting for 32 -bit 23

TIMx prescaler (TIMx_PSC) 24

TIMx Options for Prescaler 25

CNT, ARR and Compare registers (CCR) with Waveform Output 26

TIMx capture/compare registers (TIMx_CCRy) 27

TIMx_CCMR 1 for output option 28

TIMx_CCMR 2 for output option OCx. CE: Output compare x clear enable OCx. M: Output compare x mode The OCx. M options for output pin: 000: 001: 010: 011: 100: 101: 110: 111: bits in TIMx_CCMRy register are used to decide the output operation. Here are the Frozen Set output to active HIGH level when TIMx_CNT=TIMx_CCRy. Set output to inactive LOW level when TIMx_CNT=TIMx_CCRy. Toggle when TIMx_CNT=TIMx_CCRy. Forced LOW. Forced HIGH. PWM mode 1. (See Chapter 11) PWM mode 2. (See Chapter 11) OCx. PE: Output compare x preload enable CCx. S: Capture/Compare x selection This bit-field defines the direction of the channel (input/output) as well as the used input. 00: CCx channel is configured as output 29

TIMx_CCER (TIMx capture/compare enable register) 30

MODER Register is used to select alternative pin functions 31

GPIOx_AFRL Register 32

STMF 466 RE Alternative Function Table for Ports A and B (See Appendix B for other Ports) 33

TIM_CCER Register (Notice the input capture) 34

TIMx_CCMR 1 and TIMx_CCMR 2 (register details are shown in the last section) 35

Inputing Signal 36

Messuring Period and Puls Width 37

Counting Pulses 38