Motorola MCU 68HC912 Bedienungsanleitung PDF herunterladen (Seite 9)

SLAA108A

SPI-Based Data Acquisition/Monitor Using the TLC2551 Serial ADC 9

SetupClock

bic.b #XTOFF, &BCSCTL1

bis.b #SELM2+SELS, &BCSCTL2

HF_WAIT ; 8MHz Crystal used - wait for stabilization

bic.b #OFIFG, &IFG1

bit.b #OFIFG, &IFG1

jnz HF_WAIT

bic.b #OFIFG, &IFG1 ; Clear Oscillator fault flag

bit.b #OFIFG, &IFG1 ; Test for clear

bis.b #001h,&P1DIR ; P1 pin 1 set to output (toggle's LED)

Setup_SPI0_Port

bis.b #00Eh,&P3SEL ; P3.1,2,3 SPI option select

bis.b #ADC_CS+FS+DAC_CS,&P3DIR ; /CS, FS = P3 output direction

bis.b #ADC_CS+FS+DAC_CS,&P3OUT ; P3.5,6,7 CS & FS set

SetupInterrupt

bic.b #02h, &P1IFG ; Clear interrupt flags

SetupSPI0

bis.b #040h,&ME1 ; Enable SPI TX/RX

mov.b #CHAR+SYNC+MM,&U0CTL ; 8-bit SPI Master

bis.b #SSEL0+SSEL1+STC,&U0TCTL

mov.b #02h,&U0BR0 ; Set SPI Baud Rate

mov.b #00h,&U0BR1 ; This give 4MHz SCLK w/ 8MHz Crystal

mov.b #00h,&U0MCTL

ret

;*********************************************************************************

COMMON INTVEC ; MSP430x11x1/MSP430F14x Interrupt vectors

;*********************************************************************************

ORG RESET_VECTOR

RESET_VEC DW RESET_ISR ; POR, ext. Reset, Watchdog

END

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Motorola MCU 68HC912 Bedienungsanleitung Seite 9