58 lines
1.9 KiB
NASM
58 lines
1.9 KiB
NASM
; Arduino terminal driver
|
|
; @author Daniele Verducci
|
|
|
|
; config (IO port 0)
|
|
DATA_REG: EQU IO_0
|
|
|
|
; variables
|
|
TERM_VAR_SPACE: EQU DRV_VAR_SPACE + 128
|
|
incoming_string: EQU TERM_VAR_SPACE
|
|
|
|
; functions
|
|
|
|
; Sends string
|
|
; @param BC Pointer to a null-terminated string first character
|
|
Term_print:
|
|
ld a, (bc) ; bc is the pointer to passed string's first char
|
|
cp 0 ; compare A content with 0 (subtract 0 from value and set zero flag Z if result is 0)
|
|
ret z ; if prev compare is true (Z flag set), string is finished, return
|
|
out (DATA_REG),a ; output char
|
|
inc bc ; increment bc to move to next char
|
|
jp Term_print
|
|
|
|
; Writes a single character
|
|
; @param A Value of character to print
|
|
Term_printc:
|
|
out (DATA_REG),a
|
|
ret
|
|
|
|
; Reads a single character
|
|
; @return A The read character
|
|
Term_readc:
|
|
in a, (DATA_REG) ; reads a character
|
|
add a, 0
|
|
jp z, Term_readc ; if char is 0 (NULL), ignores it and waits for another character
|
|
ret ; if not NULL, returns it in the a register
|
|
|
|
; Reads a line
|
|
; @return BC The pointer to a null-terminated read string
|
|
Term_readline:
|
|
ld bc, incoming_string ; this array will contain read string
|
|
in a, (DATA_REG) ; reads a character
|
|
; if char is 0 (ascii NULL), ignore it
|
|
add a, 0
|
|
jp z, Term_readline ; if 0 (= ascii NULL), ignores it and waits for another character
|
|
; if char is a newline (CR or LF), line is finished.
|
|
cp 10 ; CR
|
|
jp z, term_readline_foundcr ; Found newline. Jump to term_readline_foundcr
|
|
cp 13 ; LF
|
|
jp z, term_readline_foundcr ; Found newline. Jump to term_readline_foundcr
|
|
; At this point the read character is a valid ascii character
|
|
ld (bc), a ; adds char to the read string
|
|
inc bc ; point to next array position
|
|
jp Term_readline
|
|
term_readline_foundcr: ; called when carriage return was found (end of line)
|
|
ld (bc), 0 ; Null-terminate string
|
|
ld bc, incoming_string ; Returns read string pointer
|
|
ret
|