diff options
| -rw-r--r-- | software/ihu/ihu.asm | 71 |
1 files changed, 59 insertions, 12 deletions
diff --git a/software/ihu/ihu.asm b/software/ihu/ihu.asm index 5258dfc..8951980 100644 --- a/software/ihu/ihu.asm +++ b/software/ihu/ihu.asm @@ -55,7 +55,9 @@ TMP EQU H'0020' TTX_BYTE EQU H'0021' TTX_BIT_CNT EQU H'0022' TTX_BYTE_CNT EQU H'0023' -WAIT_CNT EQU H'0024' +TTX_CSUM EQU H'0024' + +WAIT_CNT EQU H'0030' BUF EQU H'0040' BUF_END EQU H'004F' @@ -123,7 +125,7 @@ init clrf PSTRCON movlw b'00010000' movwf OSCCON - movlw b'00001111' + movlw b'10001111' movwf TRISD movlw b'00100100' movwf TXSTA @@ -193,9 +195,10 @@ ttx_send_byte bcf TRISD,TTX_SDA bcf STATUS,RP0 movwf TTX_BYTE + xorwf TTX_CSUM,f movlw .8 movwf TTX_BIT_CNT -ttx_next_bit +ttx_send_next_bit btfsc TTX_BYTE,7 bsf PORTD,TTX_SDA btfss TTX_BYTE,7 @@ -211,13 +214,45 @@ ttx_next_bit nop rlf TTX_BYTE,f decfsz TTX_BIT_CNT,f - goto ttx_next_bit + goto ttx_send_next_bit bsf STATUS,RP0 bsf TRISD,TTX_SDA bcf STATUS,RP0 return ;; ------------------------------------- +ttx_recv_byte + movlw .8 + movwf TTX_BIT_CNT +ttx_recv_next_bit + bsf PORTD,TTX_SCL + nop + nop + nop + bcf PORTD,TTX_SCL + nop + nop + btfsc PORTD,TTX_SDA + bsf TTX_BYTE,0 + btfss PORTD,TTX_SDA + bcf TTX_BYTE,0 + nop + nop + rlf TTX_BYTE,f + decfsz TTX_BIT_CNT,f + goto ttx_recv_next_bit + return + + ;; ------------------------------------- +ttx_break + movlw .13 + movwf TTX_BIT_CNT +ttx_wait_octet + decfsz TTX_BIT_CNT,f + goto ttx_wait_octet + return + + ;; ------------------------------------- ttx_send_frame movwf TTX_BYTE andlw b'00001111' @@ -227,6 +262,7 @@ ttx_send_frame bcf PORTD,TTX_SCL call wait_ms + clrf TTX_CSUM movf TTX_BYTE,w call ttx_send_byte @@ -235,21 +271,29 @@ ttx_send_frame return ttx_next_byte - movlw .16 - movwf TTX_BIT_CNT -ttx_wait_octet - decfsz TTX_BIT_CNT,f - goto ttx_wait_octet - + call ttx_break movf INDF,w call ttx_send_byte incf FSR,f decfsz TTX_BYTE_CNT,f goto ttx_next_byte - + + call ttx_break + call ttx_recv_byte + movf TTX_BYTE,w + xorwf TTX_CSUM,w + btfss STATUS,Z + goto ttx_csum_error return +ttx_csum_error + bcf PORTD,TTX_RESET ;reset TTX + nop + nop + bsf PORTD,TTX_RESET + return + ;; ------------------------------------- ;; MAINLOOP main @@ -259,8 +303,11 @@ main movlw BUF movwf FSR - movlw b'00010000' + movlw b'10101010' + movwf INDF + movlw b'00010001' call ttx_send_frame + clrf TMP goto main |