TV Converter Box User Manual

Software Overview

62 SLAA040

.elseif (R4BIT_RESOLUT)

@CR1_SEND ^= #RES_10_BIT ; clear bit for 10–Bit Resolution

@CR1_SEND |= #RES_4_BIT ; set 8–Bit conversion mode

.endif

.if (EXTERNAL_CLOCK)

@CR0_SEND ^= #CLK_INTERNAL ; clear CLK_INTERNAL bit if one

@CR0_SEND |= #CLK_EXTERNAL ; set CLK_EXTERNAL mode

.endif

.if (AUTO_PWDN_ENABLE)

@CR1_SEND ^= #NO_AUTO_PWDN ; clear NO_AUTO_PWDN bit if one

@CR1_SEND |= #AUTO_PWDN ; set AUTO_PWDN mode

.endif

.if (DIFF_INPUT_MODE)

@CR0_SEND ^= #SINGLE_END ; clear single ended input bit if one

@CR0_SEND |= #DIFFERENTIAL ; set differential input mode

.endif

.if (IME_CALIBRATION)

call CALIBRAT_INTERNAL_MID_SCALE

.endif

.if (SME_CALIBRATION)

call CALIBRAT_SYSTEM_MID_SCALE

.endif

****************************

* ADC_INI:

* set ADC register CR0/CR1

****************************

ADC_INI:

* write CR1 (to reset old CSTART

mode initialization, because otherwise, the ADC never sets

* back its int– pin to show a sample is available:

port(ADC) = @CR_PROBLEM ; Address decoder sets CS

low,

; WR– low and send CR_PROBLEM value to the ADC

NOP ; wait for tW(CSH)=50ns

* write CR1:

port(ADC) = @CR1_SEND ; Address decoder sets CS

low,

; WR– low and send CR1 value to the ADC

port(DEACTIVE) = @ZERO ; deselect ADC (CS

high)

NOP ; wait for tW(CSH)=50ns