;______________________________________________________________________________ ; ; PROGRAM : XTALL_Si570_Psdr.asm ; ; HARDWARE : 12F683 @ 4 MHz ; ASSEMBLER : MPASM v5.01 / case sensitive ; ; NEEDS : P12F683.INC ; ; AUTHOR : Cesco HB9TLK ; Francis F6HSI ; ;______________________________________________________________________________ ; ; DIRECTIVES ;______________________________________________________________________________ list p = 12F683, n = 0 , r = dec , x = OFF, st = ON include P12F683.INC __config _FCMEN_OFF & _IESO_OFF & _BOD_OFF & _CPD_OFF & _CP_OFF & _MCLRE_OFF & _PWRTE_ON & _WDT_OFF & _INTOSC ;______________________________________________________________________________ ; ; CONSTANTS ;______________________________________________________________________________ #define SCL GPIO,5 ; IIC Clock (pin 2) #define SDA GPIO,4 ; IIC Data (pin 3) #define SIN GPIO,3 ; RS232 Input (pin 4) #define SCL_H bsf SCL #define SCL_L bcf SCL #define Bank_0 bcf STATUS,RP0 #define Bank_1 bsf STATUS,RP0 #define SdaIn bsf TRISIO,4 #define SdaOut bcf TRISIO,4 ;______________________________________________________________________________ ; ; Variables ;______________________________________________________________________________ Temp equ 0x21 BitCount equ 0x22 rs232in equ 0x23 ;empfangenes byte d1 equ 0x26 d2 equ 0x27 d3 equ 0x28 d4 equ 0x29 d5 equ 0x2a d6 equ 0x2b Buffer equ 0xa0 ;This is in bank 1 ;______________________________________________________________________________ ; ; Program ;______________________________________________________________________________ ORG 0 clrf STATUS Init: movlw b'00000111' ; movwf CMCON0 ;digital I/O bsf STATUS,RP0 ;bank 1 clrf ANSEL ;digital I/O movlw b'01100001' ; movwf OSCCON ;4-mhz INTOSC system clock movlw b'00001111' ;GP5 output, all others output movwf TRISIO movlw B'00000000' movwf OPTION_REG bcf STATUS,RP0 ;bank 0 movlw B'00110000' movwf GPIO tst: call Freeze call I2C_Start movlw 0xAA ; Send slave address + write bit call I2C_Tx movlw 0x7 ; Send register address call I2C_Tx movlw 0xE3 call I2C_Tx ; -> reg 7 movlw 0xC2 call I2C_Tx ; -> reg 8 movlw 0xB6 call I2C_Tx ; -> reg 9 movlw 0xDA call I2C_Tx ; -> reg 10 movlw 0x33 call I2C_Tx ; -> reg 11 movlw 0x24 call I2C_Tx ; -> reg 12 call I2C_Stop call Unfreeze call Newf Loop: Serial: call ser_RX ; Code von RS232 empfangen movlw 0x08 subwf rs232in,0 ; Compare to 0x08 btfss STATUS,Z goto Serial ; No, was something else call ser_RX ; get next, should be 0xaa movlw 0xaa subwf rs232in,0 ; Compare to 0xaa btfss STATUS,Z goto Serial ; No, was something else call ser_RX ; get next, should be 0x07 movlw 0x07 subwf rs232in,0 ; Compare to 0x07 btfss STATUS,Z goto Serial ; No, was something else call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d1 ; store it. call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d2 ; store it. call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d3 ; store it. call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d4 ; store it. call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d5 ; store it. call ser_RX ; Code von RS232 empfangen movfw rs232in movwf d6 ; store it. WriteSi570: ; Download values to the Si570 call Freeze call I2C_Start movlw 0xAA ; Send slave address + write bit call I2C_Tx movlw 0x7 ; Send register address call I2C_Tx movfw d1 ; Send register values call I2C_Tx ; -> reg 7 movfw d2 call I2C_Tx ; -> reg 8 movfw d3 call I2C_Tx ; -> reg 9 movfw d4 call I2C_Tx ; -> reg 10 movfw d5 call I2C_Tx ; -> reg 11 movfw d6 call I2C_Tx ; -> reg 12 call I2C_Stop call Unfreeze call Newf goto Loop ;______________________________________________________________________________ I2C_Start: ; Wenn SDA und SCL beide High, dann SDA auf Low ziehen SCL_H bcf SDA ; Clear latch Bank_1 SdaIn ; Set SDA as input nop nop SdaOut ; Set SDA as output Bank_0 nop SCL_L RETURN ;------------------------------------------------------------------------------ I2C_Stop: ; SCL ist Low und SDA ist Low nop nop SCL_H nop Bank_1 SdaIn ; Set SDA as input Bank_0 RETURN ;------------------------------------------------------------------------------ I2C_Tx: ; Send a byte (in w) to the slave Bank_1 movwf Buffer Bank_0 movlw 8 ; I2C_Bit_Count = 8 movwf BitCount Tx_Repeat: bcf SDA ; Clear latch Bank_1 rlf Buffer,f btfss STATUS,C SdaOut ; Set SDA as output btfsc STATUS,C SdaIn ; Set SDA as input Bank_0 SCL_H ; SCL pulse nop nop nop SCL_L decfsz BitCount,f goto Tx_Repeat ; Get ACK from slave Bank_1 SdaIn ; Set SDA as input Bank_0 SCL_H nop nop nop SCL_L bcf SDA ; Clear latch Bank_1 SdaOut ; Set SDA as output Bank_0 return ;------------------------------------------------------------------------------ Newf: ; Set the NewFreq bit (bit 6 of Register 135) call I2C_Start movlw 0xAA ; Send slave address call I2C_Tx movlw 135 ; Send register address call I2C_Tx movlw b'01000000' ; Set bit 6 call I2C_Tx call I2C_Stop RETURN ;------------------------------------------------------------------------------ Freeze: ; Freeze the DCO (bit 4 of Register 137) call I2C_Start movlw 0xAA ; Send slave address call I2C_Tx movlw 137 ; Send register address call I2C_Tx movlw b'00010000' ; Set bit 4 call I2C_Tx call I2C_Stop RETURN ;------------------------------------------------------------------------------ Unfreeze: ; UnFreeze the DCO (bit 4 of Register 137) call I2C_Start movlw 0xAA ; Send slave address call I2C_Tx movlw 137 ; Send register address call I2C_Tx movlw b'00000000' ; Clear bit 4 call I2C_Tx call I2C_Stop RETURN ;______________________________________________________________________________ ser_RX: ;empfangen eines Byte nach 'byte', 'rs232in' und w clrf rs232in ;! Nullsetzen movlw 8 movwf BitCount ; 8 mal startbit: btfss SIN ; warten bis Startbit goto startbit call Pause ; Zeitverzögerung 1/2 Bit btfss SIN goto ser_RX RX_2: call Warte ; Zeitverzögerung 1 Bit btfsc SIN ; bcf STATUS, C ; high -> 0 btfss SIN ; bsf STATUS, C ; low -> 1 ; rrf rs232in, f ; decfsz BitCount, f ; goto RX_2 ; 8 mal call Warte ; Zeitverzoegerung 1 bit btfsc SIN ; Stop-Bit goto ser_RX ; wenn kein StopBit RETURN ;______________________________________________________________________________ ;ein bit zeitverzoegerung ; dieses timing muß genau stimmen (5%) ; ; empfang 4 MHz 10 MHz ; 2400 Bps = 69d 173d ; 4800 Bps = 34d 86d ; 9600 Bps = 16d 43d ;9600 bps = 0.10416 ms ;6*16 = 96 - because there are 10 more cycles in the loop -> 86/6 = 14.5 ;6*32 = 192 - because there are 10 more cycles in the loop -> 182/6 = 30.5 Warte: movlw D'31' ; 4800 Bps / 4 MHz empfangen movwf Temp Warte1: ; 6 Zyklen-Schleife nop nop nop decfsz Temp, 1 goto Warte1 RETURN ;______________________________________________________________________________ ;1/2 bit zeitverzoegerung ; ; 4 MHz 10 MHz ; 2400 Bps = 416T = 63d 157d ; 4800 Bps = 31d 78d ; 9600 Bps = 15d 39d Pause: movlw D'31' ; 4800 Bps / 4 MHz movwf Temp Pause2: ; 3 Zyklen Schleife decfsz Temp, f goto Pause2 RETURN ;______________________________________________________________________________ end