Datasheet

Chapter 6 XGATE (S12XGATEV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
294 Freescale Semiconductor
;###########################################
;# XGATE DATA #
;###########################################
ALIGN 1
XGATE_DATA_FLASH EQU *
XGATE_DATA_SCI EQU *-XGATE_DATA_FLASH
DW SCI_REGS ;pointer to SCI register space
XGATE_DATA_IDX EQU *-XGATE_DATA_FLASH
DB XGATE_DATA_MSG ;string pointer
XGATE_DATA_MSG EQU *-XGATE_DATA_FLASH
FCC "Hello World! ;ASCII string
DB $0D ;CR
;###########################################
;# XGATE CODE #
;###########################################
ALIGN 1
XGATE_CODE_FLASH LDW R2,(R1,#XGATE_DATA_SCI);SCI -> R2
LDB R3,(R1,#XGATE_DATA_IDX);msg -> R3
LDB R4,(R1,R3+) ;curr. char -> R4
STB R3,(R1,#XGATE_DATA_IDX);R3 -> idx
LDB R0,(R2,#(SCISR1-SCI_REGS));initiate SCI transmit
STB R4,(R2,#(SCIDRL-SCI_REGS));initiate SCI transmit
CMPL R4,#$0D
BEQ XGATE_CODE_DONE
RTS
XGATE_CODE_DONE LDL R4,#$00 ;disable SCI interrupts
STB R4,(R2,#(SCICR2-SCI_REGS))
LDL R3,#XGATE_DATA_MSG;reset R3
STB R3,(R1,#XGATE_DATA_IDX)
XGATE_CODE_FLASH_END RTS
XGATE_DUMMY_ISR_XG EQU (XGATE_CODE_FLASH_END-XGATE_CODE_FLASH)+XGATE_CODE_XG