New program for test transmission from PIC USART to PC serial port

diff --git a/cebpic/send-serial.asm b/cebpic/send-serial.asm
new file mode 100644 (file)
index 0000000..7b08b0e
--- /dev/null
+++ b/cebpic/send-serial.asm
@@ -0,0 +1,82 @@
+; pin 21 (per-pic-led, RD2/PSP2/C1IN) states: high H = green, low L = red, float Z = black
+
+        include         /usr/share/gputils/header/p18f458.inc
+
+       code
+start
+; initial config
+        bcf     TXSTA,6,0      ; p181, set 8-bit mode
+       bsf     TXSTA,5,0       ; transmit enable
+       bcf     TXSTA,4,0       ; asynchronous mode
+       bsf     TXSTA,2,0       ; set high baud rate
+        bsf    RCSTA,7,0       ; serial port enable (p182)
+
+; set SPBRG to get correct baud rate according to table top right p186
+; (Tosc = 20MHz, desired baud rate = 9600)
+
+       bsf     SPBRG,7,0
+       bsf     SPBRG,0,0
+
+       call    initialise-ascii
+
+main
+       movff   00h,TXREG       ; move 00h to transmit buffer (ascii s)
+       call    wait-for-tsr
+       movff   01h,TXREG       ; move 01h to transmit buffer (ascii q)
+       call    wait-for-tsr
+       movff   02h,TXREG       ; move 02h to transmit buffer (ascii o)
+       call    wait-for-tsr
+       movff   02h,TXREG       ; move 02h to transmit buffer (ascii o)
+       call    wait-for-tsr
+       movff   03h,TXREG       ; move 03h to transmit buffer (ascii k)
+       call    wait-for-tsr
+       movff   04h,TXREG       ; move 04h to transmit buffer (ascii SPACE)
+       call    wait-for-tsr
+       goto    main
+
+       
+wait-for-tsr
+       btfss   TXSTA,1,0       ; check whether TRMT is set (i.e. TSR is empty)
+       bra     wait-for-tsr
+       return
+
+
+initialise-ascii       ; set up ascii letter bytes 
+
+; there must be a faster way to do this...
+
+       crlf    00h,0   ; clear data registers
+       crlf    01h,0
+       crlf    02h,0
+       crlf    03h,0
+       crlf    04h,0
+       
+       bsf     00h,6,0 ; set 00h to be ascii s
+       bsf     00h,5,0 
+       bsf     00h,4,0
+       bsf     00h,1,0
+       bsf     00h,0,0
+       
+       bsf     01h,6,0 ; set 01h to be ascii q
+       bsf     01h,5,0 
+       bsf     01h,4,0
+       bsf     01h,0,0
+
+       bsf     02h,6,0 ; set 01h to be ascii o
+       bsf     02h,5,0
+       bsf     02h,3,0
+       bsf     02h,2,0
+       bsf     02h,1,0
+       bsf     02h,0,0
+
+       bsf     03h,6,0 ; set 03h to be ascii k
+       bsf     03h,5,0
+       bsf     03h,3,0
+       bsf     03h,1,0
+       bsf     03h,0,0
+
+       bsf     04h,5,0 ; set 04h to be ascii _
+
+       return
+
+       end