SLAS191A Datasheet, PDF (73/86 Pages) Texas Instruments – Starter Kit Evaluation Kit Manual

In Figure 5–3, the endless loop at the end of the program can be interrupted by pressing <ESC> in the
HyperTerminal. If no special treatment of <ESC> is required in the software UART, bit 0 in RAM location 200h
must be cleared. This bit is the ESC-active-flag and allows itself to return back to the Hyperterminal when
pressing the ESC key.
Conditions for implementation:
• Correct setting of the P0.1 interrupt vector in the user interrupt vector table
• The first statement of the user interrupt handler is an absolute branch to the INT_RXTX interrupt
service routine.
• GIE is enabled.
• The halfduplex software UART is set up to receive.
NOTE: Clear the Bit Pattern AA55h
Do not try to load a program while the bit pattern AA55h is stored at address 3DEh on
the MSP430x32x, or 5DEh on the MSP430x33x. To load a new program, clear the bit
pattern AA55h at address 3DEh on the MSP430x32x, or 5DEh on the MSP430x33x, or
switch off the STK/EVK for a short time to clear the RAM.
5.5 Transmitting a String
The first step to transmit a string is to move the bit pattern AA55h to memory location 3DEh on the
MSP430x32x, or 5DEh on the MSP430x33x. The address of the string must be stored in register R11.
The following program transmits the TEST String:
WDTCTL
WDTHold
WDT_wrkey
TXCHAR
TXTABLE
PREPRX
PREPTX
INT_RXTX
TXDATA
RXBUF
.equ 0120h
.equ 80h
.equ 05a00h
.equ 0FFD2h
.equ 0FFD4h
.equ 0FFD6h
.equ 0FFD8h
.equ 0FFDAh
.equ 020Eh
.equ 0210h
STRING:
RESET:
TX:
;
.data 0300h
.string “TEST”
.byte
0h
.text
0240h
MOV
#03DEh,SP
; #05DEh on the MSP430X33x
MOV
#(WDTHold+WDT_wrkey),&WDTCTL ; stop Watchdog Timer
EINT
; enable interrupt
MOV
#0AA55h,&03DEh ; prepare software UART for the
; use in user application
(&05DEh on the MSP430X33x
MOV
#STRING,R11
; Test: TX_table
BIC
#01h,&200h
; use only if no special
; treatment of ESC is wanted
CALL
&TXTABLE
; call transmit sub-routine in
; monitor
(05DEh on the MSP430X33x
CALL
&PREPRX
; prepare software UART for
5–7