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view src/ms5541.asm @ 634:4050675965ea
3.10 stable release
| author | heinrichsweikamp |
|---|---|
| date | Tue, 28 Apr 2020 17:34:31 +0200 |
| parents | 185ba2f91f59 |
| children | 7d8a4c60ec1a 5b7fe7777425 |
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;============================================================================= ; ; File ms5541.asm * combined next generation V3.9.4f ; ; Sensor Subroutines ; ; Copyright (c) 2011, JD Gascuel, HeinrichsWeikamp, all right reserved. ;============================================================================= ; HISTORY ; 2011-08-03 : [mH] moving from OSTC code #include "hwos.inc" ; Mandatory header #include "math.inc" ; Math routines ms5541 CODE ; Expose internal variables to ease debug global D1, D2 global C1, C2, C3, C4, C5, C6 global xdT, xdT2, OFF, SENS, pressure_abs_avg, temperature_avg ;----------------------------------------------------------------------------- ; Convert Temperature & Pressure raw Values to compensated Values ; ; called from ISR and from sleep mode, returns in bank isr_data ; global calculate_compensation calculate_compensation: banksel isr_backup ; select bank ISR data ;---- pressure sensor compensation ; xdT = D2 - C5 (s16 range -11.400 .. +12.350) movf C5+0,W ; get value to be subtracted subwf D2+0,W ; do the low byte movwf xdT+0 movf C5+1,W ; do the high byte subwfb D2+1,W movwf xdT+1 ; second order temperature calculation ; xdT/128 is in range -89..+96, hence signed 8 bit. dT/128 = (2*dT)/256 rlcf xdT+0,W ; put hit bit in carry rlcf xdT+1,W ; inject in high byte movwf isr_xA+0 ; and put result in low byte clrf isr_xA+1 btfsc xdT+1,7 ; dT < 0 ? setf isr_xA+1 ; YES - sign extend to -1 MOVII isr_xA,isr_xB ; copy A to B call isr_signed_mult16x16 ; dT*dT --> xC (32 bits) ; dT >= 0: divide by 8, i.e. 3 shifts rights ; dT < 0: divide by 2, i.e. 1 shifts rights movlw .3 ; 3 shifts by default btfss xdT+1,7 ; was dT negative ? movlw .1 ; YES - replace by 1 shift calc_loop_1: bcf STATUS,C ; dT^2 is positive, so injecte zeros rrcf isr_xC+1,F ; shift right high byte rrcf isr_xC+0,F ; shift right low byte decfsz WREG ; decrement loop counter, all shifts done? bra calc_loop_1 ; NO - loop movf isr_xC+0,W ; dT2 = dT - (dT/128)*(dT/128)/(2 ...or... 8) subwf xdT+0,W ; ... movwf xdT2+0 ; ... movf isr_xC+1,W ; ... subwfb xdT+1,W ; ... movwf xdT2+1 ; ... ; calculate OFF = C2 + ((C4-250)*dT2)/2^12 + 10000 (range +9.246 .. +18.887) MOVII C4, isr_xA ; C4 - 250 --> A MOVII xdT2,isr_xB ; dT2 --> B call isr_signed_mult16x16 ; C = A*B movlw .12-.8 ; a 12 bit shift = 1 byte + 4 bits call isr_shift_C31 ; special shift movlw LOW(.10000) ; add 10000 addwf isr_xC+1,F ; ... movlw HIGH(.10000) ; ... addwfc isr_xC+2,F ; ... movf C2+0,W ; add C2 and store result in OFF addwf isr_xC+1,W ; ... movwf OFF+0 ; ... movf C2+1,W ; ... addwfc isr_xC+2,W ; ... movwf OFF+1 ; ... ; calculate SENS = C1/2 + ((C3+200)*dT)/2^13 + 3000 movlw LOW(.200) ; C3+200 --> A addwf C3+0,W ; ... movwf isr_xA+0 ; ... movlw HIGH(.200) ; ... addwfc C3+1,W ; ... movwf isr_xA+1 ; ... ; B still contains dT2 call isr_signed_mult16x16 ; C = A*B movlw .13-.8 ; A 13 bit shift = 1 byte + 5 bits call isr_shift_C31 ; special shift bcf STATUS,C ; SENS = C1 / 2 rrcf C1+1,W ; ... movwf SENS+1 ; ... rrcf C1+0,W ; ... movwf SENS+0 ; ... movlw LOW(.3000) ; add 3000 addwf isr_xC+1,F ; ... movlw HIGH(.3000) ; ... addwfc isr_xC+2,F ; ... movf isr_xC+1,W ; and sum into SENS addwf SENS+0,F ; ... movf isr_xC+2,W ; ... addwfc SENS+1,F ; ... ; calculate absolute pressure = (sens * (d1-off))/2^12 + 1000 (for MS5541C) ; calculate absolute pressure = (sens * (d1-off))/2^11 + 1000 (for MS5541C-30) movf OFF+0,W ; d1-off --> a subwf D1+0,W ; ... movwf isr_xA+0 ; ... movf OFF+1,W ; ... subwfb D1+1,W ; ... movwf isr_xA+1 ; ... MOVII SENS,isr_xB ; sens --> B call isr_signed_mult16x16 ; C = A*B movlw .13 ; 12 * 256 = 3328 cpfslt C1+1 ; C1 > 3328 ? bra isr_shift_ms5541_30 ; YES - MS5541-30 movlw .12-.8 ; NO - MS5541: 12 bit shift = 1 byte + 4 bits bra isr_shift_ms5541_common ; - continue isr_shift_ms5541_30: movlw .11-.8 ; MS5541-30: 11 bit shift = 1 byte + 3 bits isr_shift_ms5541_common: call isr_shift_C31 ; special shift movlw LOW .1000 ; add 1000 addwf isr_xC+1,F ; ... movlw HIGH .1000 ; ... addwfc isr_xC+2,F ; ... ; add opt_pressure_adjust to result (SIGNED!) clrf isr_xC+0 ; prepare high byte for adjustment movff opt_pressure_adjust,WREG ; get low byte for adjustment (signed) movf WREG,W ; excite flags bz calc_compensation_1 ; opt_pressure_adjust = 0 -> skip adjustment btfss STATUS,N ; opt_pressure_adjust < 0 ? bra calc_compensation_adjust ; NO - positive negf WREG ; YES - negate opt_pressure_adjust for limit check setf isr_xC+0 ; - adopt high byte for adjustment calc_compensation_adjust: addlw -.21 ; limit is 20 mbar, subtract 21 bnn calc_compensation_1 ; result not negative -> skip adjustment movff opt_pressure_adjust,WREG ; get opt_pressure_adjust, low byte addwf isr_xC+1,F ; pressure value += opt_pressure_adjust, low byte movf isr_xC+0,W ; get adjustment, high byte addwfc isr_xC+2,F ; pressure value += opt_pressure_adjust, high byte calc_compensation_1: bcf sensor_override_active ; clear sensor override active flag by default btfss sensor_override_request ; sensor override requested? bra calc_compensation_add_avg ; NO - keep taking absolute pressure from sensor btfsc quit_simulatormode ; YES - shall quit simulator mode (the fast way)? bra calc_compensation_sim_quit ; YES - force pressure_rel_sim to zero ;bra calc_compensation_sim ; NO - calculate pressure_rel_sim from simulated depth calc_compensation_sim: ; check if OSTC got submerged movlw .5 ; coding in high byte for 1280 cpfsgt isr_xC+2 ; absolute pressure > 1280 mbar, i.e. OSTC submerged? bra calc_compensation_sim_slave ; NO - slave pressure_rel_sim to target depth ;bra calc_compensation_sim_quit ; YES - force pressure_rel_sim to zero calc_compensation_sim_quit: CLRI pressure_rel_sim ; set pressure_rel_sim to zero, this paves a restart into surface/dive mode bra calc_compensation_sim_com ; continue with common part calc_compensation_sim_slave: movf simulatormode_depth,W ; copy simulated depth to WREG mullw .100 ; multiply with 100 to turn depth from meters to relative target pressure in mbar ; check if shall go up movf pressure_rel_sim+0,W ; get relative pressure, low byte subwf PRODL,W ; WREG = relative target pressure - pressure_rel_sim (low byte) movf pressure_rel_sim+1,W ; get relative pressure, high byte subwfb PRODH,W ; WREG = relative target pressure - pressure_rel_sim (high byte) btfsc STATUS,N ; result < 0, i.e. pressure_rel_sim > relative target pressure ? bra calc_compensation_sim_up ; YES - decrease pressure_rel_sim ; check if shall go down movf PRODL,W ; get relative target pressure, low byte subwf pressure_rel_sim+0,W ; WREG = pressure_rel_sim - relative target pressure (low byte) movf PRODH,W ; get relative target pressure, high byte subwfb pressure_rel_sim+1,W ; WREG = pressure_rel_sim - relative target pressure (high byte) btfsc STATUS,N ; result < 0, i.e. relative target pressure > pressure_rel_sim ? bra calc_compensation_sim_down ; YES - increase pressure_rel_sim ; both pressures are equal bra calc_compensation_sim_com ; NO to both - keep pressure_rel_sim as it is calc_compensation_sim_up: movf PRODL,W ; get relative target pressure, low byte subwf pressure_rel_sim+0,W ; WREG = pressure_rel_sim - relative target pressure (low byte) movwf PRODL ; PRODL = pressure_rel_sim - relative target pressure (low byte) movf PRODH,W ; get relative target pressure, high byte subwfb pressure_rel_sim+1,W ; WREG = pressure_rel_sim - relative target pressure (high byte) tstfsz WREG ; more than 255 mbar off from target? bra calc_compensation_sim_up_norm ; YES - go up with normal speed movlw simulator_ascent_threshold ; NO - get remaining difference for slowing down ascent cpfslt PRODL ; - remaining difference to target < decrement? bra calc_compensation_sim_up_norm ; NO - go up with normal speed ;bra calc_compensation_sim_up_slow ; YES - go up with slow speed calc_compensation_sim_up_slow: DECI pressure_rel_sim ; subtract slow decrement (1 mbar) from pressure_rel_sim bra calc_compensation_sim_com ; continue with common part calc_compensation_sim_up_norm: SUBLI simulator_ascent_rate,pressure_rel_sim ; subtract normal decrement from pressure_rel_sim bra calc_compensation_sim_com ; continue with common part calc_compensation_sim_down: movf pressure_rel_sim+0,W ; get relative pressure, low byte subwf PRODL,F ; PRODL = relative target pressure - pressure_rel_sim (low byte) movf pressure_rel_sim+1,W ; get relative pressure, high byte subwfb PRODH,W ; WREG = relative target pressure - pressure_rel_sim (high byte) tstfsz WREG ; more than 255 mbar off from target? bra calc_compensation_sim_down_norm ; YES - go down with normal speed movlw simulator_descent_threshold ; NO - get remaining difference for slowing down descent cpfslt PRODL ; - remaining difference to target < increment? bra calc_compensation_sim_down_norm ; NO - go down with normal speed ;bra calc_compensation_sim_down_slow ; YES - go down with slow speed calc_compensation_sim_down_slow: INCI pressure_rel_sim ; add slow increment (1 mbar) to pressure_rel_sim bra calc_compensation_sim_com ; continue with common part calc_compensation_sim_down_norm: ADDLI simulator_descent_rate,pressure_rel_sim ; add normal increment to pressure_rel_sim ;bra calc_compensation_sim_com ; continue with common part calc_compensation_sim_com: movf pressure_surf+0,W ; copy surface pressure to WREG, low byte addwf pressure_rel_sim+0,W ; add surface pressure to relative pressure to gain simulated absolute pressure, low byte movwf isr_xC+1 ; override sensor pressure with simulated pressure, low byte movf pressure_surf+1,W ; copy surface pressure to WREG, high byte addwfc pressure_rel_sim+1,W ; add surface pressure to relative pressure to gain simulated absolute pressure, high byte movwf isr_xC+2 ; override sensor pressure with simulated pressure, high byte bsf sensor_override_active ; confirm sensor override is active calc_compensation_add_avg: ; add current absolute pressure to averaging buffer movf isr_xC+1,W ; copy current absolute pressure to WREG, low byte addwf pressure_abs_avg+0,F ; pressure_abs_avg += current pressure, low byte movf isr_xC+2,W ; copy current absolute pressure to WREG, high byte addwfc pressure_abs_avg+1,F ; pressure_abs_avg += current pressure, high byte ;---- temperature sensor compensation ; calculate temp = 200 + dT*(C6+100)/2^11 movlw LOW(.100) ; C6 + 100 --> A addwf C6+0,W ; ... movwf isr_xA+0 ; ... movlw HIGH(.100) ; ... addwfc C6+1,W ; ... movwf isr_xA+1 ; ... MOVII xdT2,isr_xB ; dT2 --> B call isr_signed_mult16x16 ; A*B movlw .11-.8 ; a 12 bit shift = 1 byte + 3 bits call isr_shift_C31 ; special shift movlw LOW(.200) ; add 200 addwf isr_xC+1,F ; ... movlw HIGH(.200) ; ... addwfc isr_xC+2,F ; ... ; add opt_temperature_adjust to result (SIGNED!) clrf isr_xC+0 ; prepare high byte for adjustment movff opt_temperature_adjust,WREG ; get low byte for adjustment (signed) movf WREG,W ; excite flags bz calc_temperature_add_avg ; opt_temperature_adjust = 0 -> skip adjustment btfss STATUS,N ; opt_temperature_adjust < 0 ? bra calc_temperature_adjust ; NO - positive negf WREG ; YES - negate opt_temperature_adjust for limit check setf isr_xC+0 ; - adopt high byte for adjustment calc_temperature_adjust: addlw -.21 ; limit is 2.0°C, subtract 21 (scaling is 0.1°C) bnn calc_temperature_add_avg ; result not negative -> skip adjustment movff opt_temperature_adjust,WREG ; get opt_temperature_adjust, low byte addwf isr_xC+1,F ; temperature value += opt_temperature_adjust, low byte movf isr_xC+0,W ; get adjustment high byte addwfc isr_xC+2,F ; temperature value += opt_temperature_adjust, high byte calc_temperature_add_avg: movf isr_xC+1,W ; copy current temperature to WREG, low byte addwf temperature_avg+0,F ; temperature_avg += current temperature, low byte movf isr_xC+2,W ; copy current temperature to WREG, high byte addwfc temperature_avg+1,F ; temperature_avg += current temperature, high byte return ; done ;----------------------------------------------------------------------------- ; Start Pressure Measurement ; ; called from ISR and sleep mode, needs to be called in bank isr_backup ; global get_pressure_start get_pressure_start: rcall reset_MS5541 ; reset the chip movlw b'10100000' ; +3*high as start and 1+low as stop movwf dbuffer ; .... movlw d'12' ; send start command rcall send_data_MS5541 ; ... return ; done ;----------------------------------------------------------------------------- ; Read Pressure Measurement Result ; ; called from ISR and sleep mode, needs to be called in bank isr_backup ; global get_pressure_value get_pressure_value: btfsc MS5541_miso ; conversion done? return ; NO - abort rcall get_2bytes_MS5541 ; YES - read result movff dMSB,D1+1 ; copy result to D1, high byte first movff dLSB,D1+0 ; ... low byte second return ; done ;----------------------------------------------------------------------------- ; Start Temperature Measurement ; ; called from ISR and sleep mode, needs to be called in bank isr_backup ; global get_temperature_start get_temperature_start: rcall reset_MS5541 ; reset chip movlw b'10010000' ; +3*high as start and 1+low as stop movwf dbuffer ; ... movlw d'12' ; send start command rcall send_data_MS5541 ; ... return ; done ;----------------------------------------------------------------------------- ; Read Pressure Measurement Result ; ; called from ISR and sleep mode, needs to be called in bank isr_backup ; global get_temperature_value get_temperature_value: btfsc MS5541_miso ; conversion done? return ; NO - done rcall get_2bytes_MS5541 ; YES - read result movff dMSB,D2+1 ; copy result to D2, high byte first movff dLSB,D2+0 ; ... low byte second return ; done ;----------------------------------------------------------------------------- ; Retrieve Calibration Data ; ; called by start, returns in bank common ; global get_calibration_data get_calibration_data: banksel isr_backup ; select bank ISR data bsf block_sensor_interrupt ; disable sensor interrupts rcall reset_MS5541 ; reset chip movlw b'01010100' ; +3*high as start and 1+low as stop movwf dbuffer ; ... movlw d'13' ; send command rcall send_data_MS5541 ; ... rcall get_2bytes_MS5541 ; read result movff dMSB,ir_s8_buffer+1 ; copy result, high byte first movff dLSB,ir_s8_buffer+0 ; copy result, low byte second movlw b'01011000' ; +3*high as start and 1+low as stop movwf dbuffer ; ... movlw d'13' ; send command rcall send_data_MS5541 ; ... rcall get_2bytes_MS5541 ; read result movff dMSB,ir_s8_buffer+3 ; copy result, high byte first movff dLSB,ir_s8_buffer+2 ; copy result, low byte second movlw b'01100100' ; +3*high as start and 1+low as stop movwf dbuffer ; ... movlw d'13' ; send command rcall send_data_MS5541 ; ... rcall get_2bytes_MS5541 ; read result movff dMSB,ir_s8_buffer+5 ; copy result, high byte first movff dLSB,ir_s8_buffer+4 ; copy result, low byte second movlw b'01101000' ; +3*high as start and 1+low as stop movwf dbuffer ; ... movlw d'13' ; send command rcall send_data_MS5541 ; ... rcall get_2bytes_MS5541 ; read result movff dMSB,ir_s8_buffer+7 ; copy result, high byte first movff dLSB,ir_s8_buffer+6 ; copy result, low byte second ; calculate C1 (16 Bit) movff ir_s8_buffer+1,C1+1 bcf STATUS,C rrcf C1+1 bcf STATUS,C rrcf C1+1 bcf STATUS,C rrcf C1+1 movff ir_s8_buffer+0,C1+0 bsf STATUS,C btfss ir_s8_buffer+1,0 bcf STATUS,C rrcf C1+0 bsf STATUS,C btfss ir_s8_buffer+1,1 bcf STATUS,C rrcf C1+0 bsf STATUS,C btfss ir_s8_buffer+1,2 bcf STATUS,C rrcf C1+0 ; calculate C2 (16 Bit) movff ir_s8_buffer+2, C2+0 bsf STATUS,C btfss ir_s8_buffer+3,0 bcf STATUS,C rrcf C2+0 bsf STATUS,C btfss ir_s8_buffer+3,1 bcf STATUS,C rrcf C2+0 bsf STATUS,C btfss ir_s8_buffer+3,2 bcf STATUS,C rrcf C2+0 bsf STATUS,C btfss ir_s8_buffer+3,3 bcf STATUS,C rrcf C2+0 bsf STATUS,C btfss ir_s8_buffer+3,4 bcf STATUS,C rrcf C2+0 bsf STATUS,C btfss ir_s8_buffer+3,5 bcf STATUS,C rrcf C2+0 movff ir_s8_buffer+3, C2+1 bsf STATUS,C btfss ir_s8_buffer+0,0 bcf STATUS,C rrcf C2+1 bsf STATUS,C btfss ir_s8_buffer+0,1 bcf STATUS,C rrcf C2+1 bsf STATUS,C btfss ir_s8_buffer+0,2 bcf STATUS,C rrcf C2+1 bcf STATUS,C rrcf C2+1 bcf STATUS,C rrcf C2+1 bcf STATUS,C rrcf C2+1 ; calculate C3 (16 Bit) movff ir_s8_buffer+5,C3+0 bsf STATUS,C btfss ir_s8_buffer+4,7 bcf STATUS,C rlcf C3+0 bsf STATUS,C btfss ir_s8_buffer+4,6 bcf STATUS,C rlcf C3+0 clrf C3+1 btfsc ir_s8_buffer+5,7 bsf C3+1,1 btfsc ir_s8_buffer+5,6 bsf C3+1,0 ; calculate C4 (16 Bit) movff ir_s8_buffer+7,C4+0 bsf STATUS,C btfss ir_s8_buffer+6,7 bcf STATUS,C rlcf C4+0 clrf C4+1 btfsc ir_s8_buffer+7,7 bsf C4+1,0 ; C4=C4-250 movlw LOW(-.250) ; C4 - 250 --> C4 addwf C4+0,W movwf C4+0 movlw -1 ; HIGH(- .250) is not understood... addwfc C4+1,W movwf C4+1 ; calculate C5 (16 Bit) movff ir_s8_buffer+4,C5+0 bcf C5+0,6 btfsc ir_s8_buffer+2,0 bsf C5+0,6 bcf C5+0,7 btfsc ir_s8_buffer+2,1 bsf C5+0,7 clrf C5+1 btfsc ir_s8_buffer+2,2 bsf C5+1,0 btfsc ir_s8_buffer+2,3 bsf C5+1,1 btfsc ir_s8_buffer+2,4 bsf C5+1,2 btfsc ir_s8_buffer+2,5 bsf C5+1,3 ; calculate C5 = UT1 ; C5 = 8*C5 + 10000 (u16 range 10.000 .. +42.760) clrf isr_xA+1 movlw d'8' movwf isr_xA+0 MOVII C5,isr_xB call isr_unsigned_mult16x16 ; isr_xA*isr_xB=isr_xC MOVII isr_xC,C5 movlw LOW d'10000' addwf C5+0,F movlw HIGH d'10000' addwfc C5+1,F ; = 8*C5 + 10000 ; calculate C6 (16Bit) clrf C6+1 movff ir_s8_buffer+6,C6+0 bcf C6+0,7 clrf sensor_state_counter ; reset state counter bcf block_sensor_interrupt ; re-enable sensor interrupts banksel common ; back to bank common return ; done ;----------------------------------------------------------------------------- ; Helper Function - Reset Chip ; reset_MS5541_one: bsf MS5541_mosi ; set MOSI bra send_clk_pulse ; send one high-low sequence on MS5541_clk and return reset_MS5541_zero: bcf MS5541_mosi ; clear MOSI bra send_clk_pulse ; send one high-low sequence on MS5541_clk and return reset_MS5541: rcall reset_MS5541_one ; 0 rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero rcall reset_MS5541_one rcall reset_MS5541_zero ; 15 rcall reset_MS5541_zero rcall reset_MS5541_zero rcall reset_MS5541_zero rcall reset_MS5541_zero rcall reset_MS5541_zero ; 20 return ;----------------------------------------------------------------------------- ; Helper Function - read 2 Byte from Chip ; get_2bytes_MS5541: movlw d'8' ; load counter for 8 bit movwf clock_count ; ... rcall recieve_loop ; receive 8 bits movff dbuffer,dMSB ; store result movlw d'8' ; load counter for 8 bit movwf clock_count ; ... rcall recieve_loop ; receive 8 bits movff dbuffer,dLSB ; store result bra send_clk_pulse ; send one high-low sequence on MS5541_clk and return ;----------------------------------------------------------------------------- ; Helper Function - read 1 Bit from Chip ; recieve_loop: rcall send_clk_pulse ; send one high-low sequence on MS5541_clk btfss MS5541_miso ; read bit = 1 ? (MSB first) bcf STATUS,C ; NO - clear carry bit btfsc MS5541_miso ; read bit = 0 ? (MSB first) bsf STATUS,C ; NO - set carry bit rlcf dbuffer,F ; shift buffer decfsz clock_count,F ; decrement counter, became zero? bra recieve_loop ; NO - loop return ; YES - done ;----------------------------------------------------------------------------- ; Helper Function - send a Clock Pulse ; send_clk_pulse: bsf MS5541_clk ; set clock nop nop nop nop nop nop bcf MS5541_clk ; release clock nop nop nop nop return ; done ;----------------------------------------------------------------------------- ; Helper Function - send a Command ; send_data_MS5541: movwf clock_count ; from WREG ; send three start bits first bcf MS5541_clk ; revoke clock nop ; wait nop ; wait bsf MS5541_mosi ; set MOSI movlw d'3' ; compute total bit counter subwf clock_count,F ; ... rcall send_clk_pulse ; send one high-low sequence on MS5541_clk rcall send_clk_pulse ; send one high-low sequence on MS5541_clk rcall send_clk_pulse ; send one high-low sequence on MS5541_clk send_data_MS5541_loop: ; now send 8 bits from dbuffer and fill-up with zeros bcf MS5541_clk ; revoke clock nop ; wait nop ; wait btfss dbuffer,7 ; bit = 1 ? (MSB first) bcf MS5541_mosi ; NO - clear MOSI btfsc dbuffer,7 ; bit = 0 ? (MSB first) bsf MS5541_mosi ; NO - set MOSI bsf MS5541_clk ; set clock bcf STATUS,C ; clear carry bit rlcf dbuffer,F ; shift data byte nop ; wait nop ; wait ; nop ; nop ; nop ; nop ; bcf MS5541_clk decfsz clock_count,F ; decrement bit counter, became zero? bra send_data_MS5541_loop ; NO - loop bcf MS5541_clk ; YES - revoke clock return ; - done ;----------------------------------------------------------------------------- END