STC15W4K32S4-PWM-2014-8-11(5)

mov A, #13H ; Write PWMCL simultaneous update PWMCH movx @DPTR, A ;

;; +-------------------------+ ;; | Channel-4 Configuration | ;; +-------------------------+

; Set toggle point 1 of Channel-4 as 3

mov DPTR, #PWM4T1H ; FF20H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM4T1L ; FF21H mov A, #03H movx @DPTR, A ;

; Set toggle point 2 of Channel-4 as 16

mov DPTR, #PWM4T2H ; FF22H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM4T2L ; FF23H mov A, #10H movx @DPTR, A ;

; Set Channel-4 output pin as default, and disable interrupting mov DPTR, #PWM4CR ; FF24H mov A, #00H movx @DPTR, A ;

; Clear EAXSFR to disable xSFR, return movx-DPTR to normal XRAM access mov A, P_SW2

anl A, #01111111B mov P_SW2, A ;

;; +-------------------------+ ;; | Operate PWM output |

;; +-------------------------+

; Enable counter counting, and enable Channel-4 output mov A, PWMCR

orl A, #10000100B mov PWMCR, A ;

汇编示例代码2

假如要生成两个互补对称输出的PWM波形，波形如下：

PWM波形发生器的时钟频率为系统时钟/4，波形由信道4和信道5输出，，周期为20个PWM时钟,通道4的有效高电平为13个PWM时钟，通道5的有效低电平为10个PWM时钟，信道4和信道5 前端死区为2个PWM时钟，末端死区为1个PWM时钟（波形如下图所示）

Pre-deadband=2Post-deadband=1Initialized @ LOWInitialized @ HIGH012345678910151619012345678910151619012345678910151619Period==(16+1) Channel-4: toggle-point-1==3(0003H) toggle-point-2==16 (0010H) Channel-5: toggle-point-1==5(0005H) toggle-point-2==15 (000FH)

汇编代码可以如下设计：

;; +-------------------------+ ;; | Global Configuration | ;; +-------------------------+

;;;

;;; Set EAXSFR to enable xSFR writing against XRAM writing ;;;

mov A, P_SW2

orl A, #10000000B mov P_SW2, A ;

; Set channel-4 output register start at LOW, channel-5 at HIGH mov A, PWMCFG

anl A, #11111011B ; channel-4 start at LOW orl A, #00001000B ; channel-5 start at HIGH mov PWMCFG, A ;

; Set a clock of the waveform generator consists of 4 Fosc mov DPTR, #PWMCKS ; FFF2H mov A, #00000011B movx @DPTR, A ;

; Set period as 20 ; {PWMCH,PWMCL} <= 19

mov DPTR, #PWMCH ; FFF0H

mov A, #00H ; PWMCH should be changed first movx @DPTR, A

mov DPTR, #PWMCL ; FFF1H

mov A, #13H ; Write PWMCL simultaneous update PWMCH movx @DPTR, A ;

;; +-------------------------+ ;; | Channel-4 Configuration |

;; +-------------------------+

; Set toggle point 1 of Channel-4 as 3

mov DPTR, #PWM4T1H ; FF20H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM4T1L ; FF21H mov A, #03H movx @DPTR, A ;

; Set toggle point 2 of Channel-4 as 16

mov DPTR, #PWM4T2H ; FF22H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM4T2L ; FF23H mov A, #10H movx @DPTR, A ;

; Set Channel-4 output pin as default, and disable interrupting mov DPTR, #PWM4CR ; FF24H mov A, #00H movx @DPTR, A ;

;; +-------------------------+ ;; | Channel-5 Configuration | ;; +-------------------------+

; Set toggle point 1 of Channel-5 as 5

mov DPTR, #PWM5T1H ; FF30H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM5T1L ; FF31H mov A, #03H movx @DPTR, A ;

; Set toggle point 3 of Channel-5 as 15

mov DPTR, #PWM5T2H ; FF32H mov A, #00H movx @DPTR, A ;

mov DPTR, #PWM5T2L ; FF33H mov A, #0FH movx @DPTR, A ;

; Set Channel-5 output pin as default, and disable interrupting mov DPTR, #PWM5CR ; FF34H mov A, #00H movx @DPTR, A ;

;;; Clear EAXSFR to disable xSFR, return movx-DPTR to normal XRAM access mov A, P_SW2

anl A, #01111111B mov P_SW2, A ;

;; +-------------------------+ ;; | Operate PWM output |

;; +-------------------------+

; Enable counter counting, and enable Channel-4 and Channel-5 output mov A, PWMCR

orl A, #10001100B mov PWMCR, A ;

两通道CCP/PCA/增强PWM

相关SFR

符号 CCON CMOD CCAPM0 CCAPM1 CL 描述 地址 D8H D9H DAH DBH E9H 位地址及符号 B7 CF CIDL - - B6 CR - ECOM0 ECOM1 B5 - - CCAPP0 CCAPP1 B4 - - CCAPN0 CCAPN1 B3 - CPS2 MAT0 MAT1 B2 - CPS1 TOG0 TOG1 B1 CCF1 CPS0 PWM0 PWM1 B0 CCF0 ECF ECCF0 ECCF1 初始值 00xx,xx00 0xxx,0000 x000,0000 x000,0000 0000,0000 CH CCAP0L CCAP0H CCAP1L CCAP1H PCA_PWM0 PCA_PWM1 F9H EAH FAH EBH FBH F2H F3H EBS0_1 …… 此处隐藏：2590字，全部文档内容请下载后查看。喜欢就下载吧 ……