PROCESSOR 68HC11 * * "DOWNLOAD" * * DESCRIPTION: * * DOWNLOAD is a monitor that resides within the EEPROM of the HC11. * Its main task is to initialize the HC11 and download S record * format files into external RAM for execution. Among initialization * tasks are the definition of the memory map and the chip selects. * All external memory locations are also tested prior to * proceeding with the monitor function. * * * INCLUDE FILES * REG_FILE EQU $9000 *START LOCATION OF REGISTER FILE INCLUDE ADev11:68HC11.INC * * * XREF SCI_JMP,SPI_JMP,PULSE_IN_JMP,PULSE_OVF_JMP,TIMER_OVF_JMP XREF TIMER_IC4_JMP,TIMER_OC4_JMP,TIMER_OC3_JMP,TIMER_OC2_JMP XREF TIMER_OC1_JMP,TIMER_IC3_JMP,TIMER_IC2_JMP,TIMER_IC1_JMP XREF RT_INTR_JMP,IRQ_JMP,XIRQ_JMP,SWI_JMP,OPC_JMP,COP_FAIL_JMP XREF MON_FAIL_JMP XREF EXT_TABLE XREF STACK,CHECKSUM,KEY1,KEY2,I_BUFFER ZPAGE_SIZE EQU $100 USR_RAM_SIZE EQU $8000-ZPAGE_SIZE STACK_SIZE EQU $100 * SEG.U EXT_RAM USR_RAM SEG EEPROM jmp GETC jmp GETS jmp PUTC jmp PUTS jmp PCRLF jmp RDBYTE jmp str_cmp START LDS #STACK+STACK_SIZE-1 LDAA #$89 HC11 ram @ $8000, regs @ $9000 STAA INIT LDX #REG_FILE LDAA #$90 enable A/D system, STOP delay on STAA OPTION-REG_FILE,X LDAA #$00 STAA PORTG-REG_FILE,X LDAA #$7F STAA DDRG-REG_FILE,X * SETUP CHIP SELECT OUTPUTS LDAA #$08 CSGEN has priority, others disabled STAA CSCTL-REG_FILE,X LDAA #$01 CSGEN accesses 32K,active low STAA CSGSIZ-REG_FILE,X LDAA #$00 STAA CSGADR-REG_FILE,X ldaa #$21 divider = 19.2 Kbaud range, baud = 9600 staa BAUD-REG_FILE,X ldaa #$0C staa SCCR2-REG_FILE,X *** MEMORY CHECKS *** mem_chk *** non-destructive read/write check LDX #USR_RAM *SETUP POINTER TO RAM NEXT_ADDR_CHK ldaa 0,X coma staa 0,X *WRITE DATA TO EXTERNAL RAM cmpa 0,X bne MEM_ERR2 coma staa 0,X cmpa 0,X bne MEM_ERR2 inx CPX #USR_RAM+USR_RAM_SIZE *CHECK IF LAST LOCATION EXCEEDED BNE NEXT_ADDR_CHK *NO, THEN CONTINUE RAM CHECK bra INIT_SYS MEM_ERR2 LDX #MEM_FAULT bsr PUTS INIT_SYS *** CHECK FOR PREVIOUS PROGRAM (BEFORE BOOT) LDD KEY1 cpd #REF_KEY1 bne INIT_CLEAR ldd KEY2 cpd #REF_KEY2 beq INIT_WITH_PROGRAM INIT_CLEAR ldd #0 *INITIALIZE PROGRAM VECTOR TO FALSE std EXT_TABLE bra SYS_START INIT_WITH_PROGRAM ldx EXT_TABLE INIT_W0 ldaa 0,x find and execute first command in program beq INIT_W1 inx bra INIT_W0 INIT_W1 inx ldx 0,x jsr 0,x * * * SYS_START bsr PCRLF MONITOR ldaa #'> bsr PUTC ldx #I_BUFFER bsr GETS *get a line of text, X -> line ldy #FUNC_TABLE jsr SCAN_FUNC_TABLE bne MONITOR *a function match was found * ldy EXT_TABLE *CHECK IF EXTERNAL TABLE SET beq MON_ERR jsr SCAN_FUNC_TABLE bne MONITOR MON_ERR ldx #NO_FUNC_STR bsr PUTS bra MONITOR * * * * GETS GETS pshx gets1 bsr GETC bsr PUTC cmpa #$D beq gets2 cmpa #$A beq gets2 staa 0,x inx bra gets1 gets2 clr 0,x bsr PCRLF pulx rts * * * GETC ldaa SCSR bita #RDRF beq GETC ldaa SCDR rts * PCRLF LDX #CRLF bra PUTS * * puts1 bsr PUTC inx PUTS ldaa 0,x bne puts1 rts * * * char in A PUTC ldab SCSR bitb #TDRE beq PUTC staa SCDR rts * * DO_S0 rts * DO_S1 bsr RD_SREC inc CHECKSUM $FF -> $00 beq NO_ERR_S1 ERR_S1 ldx #CHK_FAIL_STR bsr PUTS NO_ERR_S1 rts * DO_S9 BSR RD_SREC inc CHECKSUM $FF -> $00 bne ERR_S1 LDD #REF_KEY1 STD KEY1 LDD #REF_KEY2 STD KEY2 jmp 0,y * RD_SREC clr CHECKSUM BSR RDBYTE *READ BYTE COUNT OF S1 RECORD INTO ACCB TBA *STORE IT IN ACCA BSR GETADR *GET LOAD ADDRESS INTO Y REGISTER SUBA #3 *REMOVE LOAD ADDRESS & CHECKSUM BYTES FROM COUNT beq RDBYTE if no data bytes read checksum NEXT_BYTE BSR RDBYTE STAB 0,Y STORE BYTE AT ADDRESS INY *ADVANCE TO NEXT LOAD ADDRESS DECA WHEN ALL BYTES read, read checksum BNE NEXT_BYTE * WARNING!!! - flows into RDBYTE * *READ DATA BYTE RDBYTE psha LDAB 2,X *1st READ MS NIBBLE INX BSR HEXBIN *CONVERT TO BINARY LSLB *AND MOVE TO UPPER NIBBLE LSLB LSLB LSLB tba LDAB 2,X *GET ASCII CHAR IN ACCB INX BSR HEXBIN aba tab adda CHECKSUM staa CHECKSUM pula RTS *RETURN WITH BYTE IN ACCB * GETADR PSHA *SAVE BYTE COUNTER BSR RDBYTE *READ MS BYTE OF ADDRESS TBA *AND PUT IT IN MSBYTE OF ACCD BSR RDBYTE *READ LS BYTE OF ADDRESS INTO LS BYTE OF ACCD XGDY *PUT LOAD ADDRESS IN Y PULA *RESTORE BYTE COUNTER RTS *AND RETURN * * *CONVERT ASCII HEX TO BINARY HEXBIN CMPB #'9 *IF ACCB>9 THEN ASSUME ITS A-F BLS HEXNUM ADDB #9 HEXNUM ANDB #$F RTS * * X must not change, Y must move to char past null, terms on null of Y str_cmp pshx str_cmp_1 ldaa 0,y beq str_cmp_pass cmpa 0,x bne str_cmp_fail inx iny bra str_cmp_1 str_cmp_fail iny ldaa 0,y bne str_cmp_fail iny ldaa #1 pulx rts str_cmp_pass iny clra pulx rts * * SCAN_FUNC_TABLE bsr str_cmp beq do_func iny iny tst 0,y bne SCAN_FUNC_TABLE rts do_func ldy 0,y jsr 0,y ldaa #1 clear Z flag rts * * * FUNC_TABLE DC.B "S0",0 DC.W DO_S0 DC.B "S1",0 DC.W DO_S1 DC.B "S9",0 DC.W DO_S9 DC.B 0 * REF_KEY2 FDB $D709 REF_KEY1 FDB $EB35 complement of inside nybbles NO_FUNC_STR FCB "Command Not Found",$D,$A,0 CHK_FAIL_STR FCB "Checksum Error" flows into next string CRLF FCB $D,$A,0 MEM_FAULT FCB "Memory Fault",0 SEG VECTORS FDB SCI_JMP FDB SPI_JMP FDB PULSE_IN_JMP FDB PULSE_OVF_JMP FDB TIMER_OVF_JMP FDB TIMER_IC4_JMP FDB TIMER_OC4_JMP FDB TIMER_OC3_JMP FDB TIMER_OC2_JMP FDB TIMER_OC1_JMP FDB TIMER_IC3_JMP FDB TIMER_IC2_JMP FDB TIMER_IC1_JMP FDB RT_INTR_JMP FDB IRQ_JMP FDB XIRQ_JMP FDB SWI_JMP FDB OPC_JMP FDB COP_FAIL_JMP FDB MON_FAIL_JMP FDB START END