C-16 – Texas Instruments TMS320C2XX User Manual
Page 501
Task-Specific Program Code
C-16
Example C–11. Testing and Using Automatic Baud-Rate Detection on
Asynchronous Serial Port (autobaud.asm)
* File:
autobaud.asm
*
* Function:
UART,auto baud test
*
*
Locks to incoming baud rate if the first character
*
*
is ”A” or ”a” & continuously echoes data received
*
*
through the port.
*
* Once detection is complete, if the CAD and ADC bits are not
*
* disabled and the interrupt is enabled, the ISR will occur for
*
* all characters received and will change the baud setting again.
*
.title ”Auto_baud detect”
; 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
#0c0a0h,61h
; reset the UART by writing 0
out
61h, aspcr
; 1 stop bit, rx interrupt, input i/o
splk
#0e0a0h,61h
; CAD=1 enable
out
61h,aspcr
splk
#4fffh,62h
; enable ADC bit
out
62h,iosr
; disable auto baud
splk
#0000h, 63h
; set baud rate =0000 @ 20-MHz CLKOUT1
out
63h, brd
splk
#20h,imr
; enable UART interrupt
mar
*,ar1
lar
ar1,#rxbuf
* Load data at DM300
lar
ar1,#rxbuf
lar
ar0, #size
; load buffer size
mar
*,ar1
; load data pointer
clrc
intm
wait:
clrc
xf
idle
b
wait