Task-Specific Program Code
C-13
Program Examples
Example C–9. Asynchronous Serial Port Transmission (uart.asm)
* File:
uart.asm
*
* Function:
UART Test Code
*
* Continuously sends ’’C203 UART is fine’ at 1200 baud.
*
.title ” UART Test”
; Title
.copy
”init.h”
; Variable and register declaration
.copy
”vector.h”
; Vector label declaration
.text
start:
clrc
CNF
; Map block B0 to data memory
ldp
#0h
; set DP=0
setc
INTM
; Disable all interrupts
* UART initialization *
splk
#0ffffh,ifr
; clear interrupts
splk
#0000h,60h
out
60h, wsgr
; Set zero wait states
splk
#0c180h,61h
; reset the UART by writing 0
out
61h, aspcr
; 1 stop bit, tx interrupt, input i/o
splk
#0e180h,61h
; Enable the serial port
out
61h,aspcr
splk
#4fffh,62h
out
62h,iosr
; disable auto baud
splk
#0411h, 63h
; set baud rate =1200 @ 20-MHz CLKOUT1
out
63h, brd
splk
#20h,imr
; enable UART interrupt
mar
*,ar1
; ARP=ar1
lar
ar1,#rxbuf
* Load data at DM300
; ’c203 UART is fine!’ – xmit data
splk
#0063h,*+
; ascii value for the above characters
splk
#0032h,*+
splk
#0030h,*+
splk
#0033h,*+
splk
#0020h,*+
splk
#0055h,*+
splk
#0041h,*+
splk
#0052h,*+
splk
#0054h,*+
splk
#0020h,*+
splk
#0069h,*+
splk
#0073h,*+
splk
#0020h,*+
splk
#0066h,*+
splk
#0069h,*+
splk
#006eh,*+
splk
#0065h,*+
splk
#0020h,*+
splk
#0021h,*+
splk
#0021h,*+
splk
#0020h,*+
