serial.asm

DTMF decoder using pic16f

; modified by Radu Constantinescu - eliminate calls in order to save stack space
; UART routines with TX and RX buffers By Tony K黚ek 2000-06-22 free for use


; handy ASCII character table
STX	EQU	0x02	; stx
ETX	EQU	0x03	; etx
BEL	EQU	0x07	; bell
BS	EQU	0x08	; backspace
TAB	EQU	0x09	; horizontal tab
LF	EQU	0x0A	; line feed
FF	EQU	0x0C	; form feed
CR	EQU	0x0D	; carriage return
XON	EQU	0x11	; transmit on
XOFF	EQU	0x13	; transmit off
EOF	EQU	0x1A	; end of file
ESC	EQU	0x1B	; escape
SP	EQU	0x20	; space

; buffers for serial communication
RX_BUFFER_SIZE	EQU	32	; serial receive buffer allocation ( best when power of 2 )
TX_BUFFER_SIZE	EQU	32	; serial transmit buffer allocation

; Baud rate constants from (((10*XTAL_FREQ/(16*BAUD))+5)/10)-1
; note these calulations uses BRGH = 1 ( high speed mode )
; for BRGH = 0 use the formula: (((10*XTAL_FREQ/(64*BAUD))+5)/10)-1
; NOTE Rather use the calculations further down below instead !
;BAUD_9600	EQU	(((10*XTAL_FREQ/(16*9600))+5)/10)-1
;BAUD_19200	EQU	(((10*XTAL_FREQ/(16*19200))+5)/10)-1
;BAUD_38400	EQU	(((10*XTAL_FREQ/(16*38400))+5)/10)-1
;BAUD_57600	EQU	(((10*XTAL_FREQ/(16*57600))+5)/10)-1
;BAUD_115200	EQU	(((10*XTAL_FREQ/(16*115200))+5)/10)-1

; caulculates baudrate when BRGH = 1, adjust for rounding errors
#define CALC_HIGH_BAUD(BaudRate)	(((10*XTAL_FREQ/(16*BaudRate))+5)/10)-1

; caulculates baudrate when BRGH = 0, adjust for rounding errors
#define CALC_LOW_BAUD(BaudRate)		(((10*XTAL_FREQ/(64*BaudRate))+5)/10)-1