使用 DAC 接口生成三角波
我们编写了一个 8085 汇编语言程序,使用数字模拟转换器 (DAC) 接口生成三角波形。波形的显示在示波器上可见。
让我们在这个领域考虑一个问题解决方案。该问题指出:为了获得单极输出,接口上的 J1 短接到 J2。要将波形显示在示波器上,将连接器 P1 的 1 号引脚连接到示波器信号引脚,将连接器 P1 的 2 号引脚连接到示波器地线引脚。
程序
; FILE NAME DAC_TO_TRIANG.ASM ORG C100H X DW 00FFH ; the fall of rise and time I proportional directly to the value. ORG C000H PA EQU D8H PB EQU D9H PC EQU DAH CTRL EQU DBH MVI A, 88H OUT CTRL ; Purpose to configure 8255 ports ; The next 7 instructions will generate rising portion of the triangular waveform. ; And it is done by sending to DAC through Port A values from 00H to FFH, ; in steps of 01. Also the increment will be done after a small time delay here. LOOP: MVI A, 00H ASCEND: OUT PA PUSH PSW CALL DELAY POP PSW INR A JNZ ASCEND DCR A ; Now A contents will be FFH DESCEND: OUT PA PUSH PSW CALL DELAY POP PSW DCR A CPI FFH JNZ DESCEND JMP LOOP ; These Subroutines are used only for the generation of delay ; which is proportional to all the contents of word located at X. DELAY: LHLD X AGAIN: DCX H MOV A, H ORA L JNZ AGAIN RET
广告