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https://opencores.org/ocsvn/k68/k68/trunk
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[/] [k68/] [trunk/] [sw/] [misc/] [68mon.s] - Rev 4
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ORG 0 DC.W 0,STACK ;RESET: initial SSP DC.W 0,START ;RESET: initial PC DC.W 0,BUS_ERROR DC.W 0,ADRS_ERROR DC.W 0,ILLEGAL_INST DC.W 0,DIV_ZERO DC.W 0,START ;CHK not implemented DC.W 0,TRAP_V ; ORG $7C ;skip reserved vectors DC.W 0,LEVEL_7 DC.W 0,TO_CHAR_IN ;TRAP vector 0 DC.W 0,TO_CHAR_OUT ;TRAP vector 1 DC.W 0,TO_CRLF ;TRAP vector 2 DC.W 0,TO_PRINT_MSG ;TRAP vector 3 DC.W 0,TO_PRINT_BYTE ;TRAP vector 4 DC.W 0,TO_PRINT_WORD ;TRAP vector 5 DC.W 0,TO_PRINT_LONG ;TRAP vector 6 DC.W 0,TO_GET_BYTE ;TRAP vector 7 DC.W 0,TO_GET_ADDR ;TRAP vector 8 DC.W 0,GETCMD ;TRAP vector 9 ; ORG $400 ;start of monitor STACK EQU $9000 START MOVEA.L #STACK,A7 ;init stack BSR INIT_ACIA ;init serial chip BSR SIGN_ON ;greet user GETCMD MOVEA.L #STACK,A7 ;init stack BSR CRLF MOVE.B #'*',D1 ;output command prompt BSR CHAR_OUT CLR.L D2 ;init command-text buffer MOVEA.L #$8F00,A6 ;load buffer location BSR GETLINE ;fill buffer with text MOVEA.L #$8F00,A6 ;reset buffer pointer BSR SKIP_BLK ;skip leading blanks INCOM MOVE.B (A6)+,D1 BSR UPPER_CASE CMPI.B #$0D,D1 BEQ SEARCH CMPI.B #$20,D1 ;test for SP BEQ SEARCH ROL.L #8,D2 ;prepare D2 for new letter MOVE.B D1,D2 ;insert it into D2 BRA INCOM ;get next letter SEARCH MOVE.L #5,D5 ;number of commands to check MOVEA.L #COMMANDS,A2 ;init command text pointer MOVEA.L #COM_ADRS,A1 ;init command address pointer TEST_NEXT CMP.L (A2),D2 ;compare command text BEQ DO_JUMP ;branch if match ADDQ.L #4,A2 ;point to abbreviated command CMP.L (A2),D2 ;test again BEQ DO_JUMP ADDQ.L #4,A2 ;point to next command ADDQ.L #4,A1 ;point to next address SUBQ.L #1,D5 ;all commands checked yet? BNE TEST_NEXT BRA ERROR ;illegal command entered DO_JUMP MOVEA.L (A1),A1 ;get command address JMP (A1) ;and go execute command COMMANDS DC.B 'DUMP' ;full command name DC.B 0,0,0 ;abbreviated name DC.B 'D' DC.B 'GO ' DC.B 0,0,0 DC.B 'G' DC.B 'EDIT' DC.B 0,0,0 DC.B 'E' DC.B 'MOVE' DC.B 0,0,0 DC.B 'M' DC.B 'HELP' DC.B 0,0,0 DC.B 'H' COM_ADRS DC.W 0,DUMP ;DUMP execution address DC.W 0,GO DC.W 0,EDIT DC.W 0,MOOV DC.W 0,HELP ; DUMP BSR GET_ADDR ;get the starting address ANDI.B #$F0,D2 ;make lower nibble zero MOVEA.L D2,A4 ;A4 is memory read register BSR GET_ADDR ;get the ending address MOVEA.L D2,A5 ADR_OUT BSR CRLF ;new line please MOVE.L A4,D2 ;print address BSR PRINT_LONG BSR BLANK ;and some blanks BSR BLANK BYTE_OUT MOVE.B (A4)+,D2 ;get a byte and increment A4 BSR PRINT_BYTE ;print the byte BSR BLANK MOVE.L A4,D1 ;done 16 yet? ANDI.L #$0F,D1 BNE BYTE_OUT SUBA.L #16,A4 ;back up 16 bytes BSR BLANK ASCII_OUT MOVE.B (A4)+,D1 ;get a byte ANDI.B #$7F,D1 CMPI.B #$20,D1 ;is it printable? BMI UN_PRINT CMPI.B #$7D,D1 BMI SEND_IT UN_PRINT MOVE.B #$2E,D1 ;use period for unprintables SEND_IT BSR CHAR_OUT ;print the ASCII equivalent MOVE.L A4,D2 ;done 16 yet? ANDI.L #$0F,D2 BNE ASCII_OUT BSR FREEZE ;hold display? CMPA.L A4,A5 ;done with dump? BMI GETCMD BRA ADR_OUT ; GO BSR GET_ADDR ;get execution address MOVEA.L D2,A1 JMP (A1) ; MOOV BSR GET_ADDR ;get starting address MOVEA.L D2,A1 BSR GET_ADDR ;get ending address MOVEA.L D2,A2 ADDA.L #1,A2 ;include last location BSR GET_ADDR ;get destination address MOVEA.L D2,A3 MOOVEM MOVE.B (A1)+,(A3)+ ;move and increment pointers CMPA.L A1,A2 ;at ending address yet? BNE MOOVEM BRA GETCMD ; EDIT BSR GET_ADDR ;get starting address MOVEA.L D2,A2 ;A2 is the memory pointer NEW_DATA BSR CRLF ;new line please MOVE.L A2,D2 ;print data address BSR PRINT_LONG BSR BLANK MOVE.B (A2),D2 ;get the data BSR PRINT_BYTE ;and show it MOVE.B #'?',D1 ;output change prompt BSR CHAR_OUT BSR GET_BYTE_T ;get new data CMPI.B #'*',D2 ;no change requested? BNE ENTER_IT ;jump if new data entered MOVE.B (A2),D1 ;get old data back ENTER_IT MOVE.B D1,(A2)+ ;save data and increment pointer BSR NEW_DATA ; INIT_ACIA MOVEA.L #$10000,A0 ;point to ACIA Control reg. MOVE.B #3,(A0) ;ACIA master reset MOVE.B #$15,(A0) ;select options RTS ; INSTAT MOVEA.L #$10000,A0 ;point to ACIA Status reg. MOVE.B (A0),D0 ;get ACIA status ANDI.B #1,D0 ;test RRDY bit RTS ; CHAR_IN BSR INSTAT ;check receiver status BEQ CHAR_IN ;loop if no character waiting MOVEA.L #$10002,A0 ;point to ACIA Data reg. MOVE.B (A0),D1 ;get the ASCII character ANDI.B #$7F,D1 ;strip off MSB RTS ; CHAR_OUT MOVEA.L #$10000,A0 ;point to ACIA Status reg. CHAR_OUT2 MOVE.B (A0),D0 ;read the ACIA status ANDI.B #2,D0 ;check the TRDY bit BEQ CHAR_OUT2 ;loop if not ready MOVEA.L #$10002,A0 ;point to ACIA Data reg. MOVE.B D1,(A0) ;send the character RTS ; CRLF MOVE.B #$0D,D1 ;send ASCII CR BSR CHAR_OUT MOVE.B #$0A,D1 ;send ASCII LF BSR CHAR_OUT RTS ; BLANK MOVE.B #$20,D1 ;send ASCII SP BSR CHAR_OUT RTS ; PRINT_MSG MOVE.B (A3),D1 ;get a character CMP.B #0,D1 ;end of message? BEQ PRINT_MSG2 BSR CHAR_OUT ;send character to display ADDQ.L #1,A3 ;point to next character BRA PRINT_MSG PRINT_MSG2 RTS ; SIGN_ON MOVEA.L #HELLO,A3 ;get starting message address BSR PRINT_MSG ;send the message RTS ; PRINT_BYTE MOVE.L D2,D1 ;init conversion register ROL.B #4,D1 ;look at upper nibble first BSR TO_ASCII ;print ASCII equivalent MOVE.L D2,D1 ;repeat for lower nibble TO_ASCII ANDI.B #$0F,D1 ;strip off upper nibble ADDI.B #$30,D1 ;add ASCII bias CMPI.B #$3A,D1 ;test for alpha conversion BMI NO_ADD ADDI.B #7,D1 ;correct to 41H-47H (A-F) NO_ADD BSR CHAR_OUT ;send character RTS ; PRINT_WORD ROL.W #8,D2 ;get upper 8 bits BSR PRINT_BYTE ;output first two characters ROL.W #8,D2 ;now do the lower 8 bits BSR PRINT_BYTE RTS ; PRINT_LONG SWAP D2 ;get upper 16 bits BSR PRINT_WORD ;do 4 character conversion SWAP D2 ;and repeat for lower word BSR PRINT_WORD RTS ; VALDIG CMPI.B #'G',D1 ;greater than F? BPL ERROR CMPI.B #'0',D1 ;less than 0? BMI ERROR CMPI.B #'9'+1,D1 ;is it now A-F? BPL NEXT_TST RTS ;range is 0-9 NEXT_TST CMPI.B #'A',D1 ;less than A? BMI ERROR RTS ;range is A-F ; ERROR MOVEA.L #WHAT,A3 ;get message pointer BSR PRINT_MSG BRA GETCMD ;restart monitor program WHAT DC.B $0D,$0A ;newline DC.B 'What?' DC.B $0D,$0A,0 ;newline and end characters ; TO_HEX SUBI.B #$30,D1 ;remove ASCII bias CMPI.B #$0A,D1 ;0-9? BMI FIN_CONV SUBI.B #7,D1 ;remove alpha bias FIN_CONV RTS ; GET_BYTE_T MOVEA.L #$8F00,A6 ;TRAP entry point BSR GETLINE MOVEA.L #$8F00,A6 GET_BYTE BSR SKIP_BLK ;MON entry point MOVE.B (A6)+,D1 ;get first digit BSR UPPER_CASE CMPI.B #$0D,D1 ;test for CR BEQ NO_CHAN CMPI.B #$20,D1 ;test for SP BEQ NO_CHAN BSR VALDIG ;check for valid digit BSR TO_HEX ;convert into hex ROL.B #4,D1 ;move first digit MOVE.B D1,D2 ;save first digit MOVE.B (A6)+,D1 ;get second digit BSR UPPER_CASE BSR VALDIG ;check for valid digit BSR TO_HEX ;convert into hex ADD.B D2,D1 ;form final result MOVE.B #'0',D2 ;change entered RTS NO_CHAN MOVE.B #'*',D2 ;no change character RTS ; GET_ADDR_T MOVEA.L #$8F00,A6 BSR GETLINE MOVEA.L #$8F00,A6 GET_ADDR BSR SKIP_BLK CLR.L D1 ;init temp register CLR.L D2 ;init result register NEXT_CHAR MOVE.B (A6)+,D1 ;get a character BSR UPPER_CASE CMPI.B #$0D,D1 ;exit if CR BEQ EXIT_ADR CMPI.B #$20,D1 ;exit if SP BEQ EXIT_ADR BSR VALDIG ;test for valid digit BSR TO_HEX ;convert digit into hex ROL.L #4,D2 ;prepare D2 for new digit ANDI.B #$F0,D2 ADD.B D1,D2 ;insert new digit BRA NEXT_CHAR ;and continue EXIT_ADR RTS ; PANIC BSR INSTAT ;check for key BEQ EXIT_BRK ;return if none hit TEST_KEY BSR CHAR_IN ;get key TEST_KEY2 CMPI.B #3,D1 ;Control-C? BEQ GETCMD ;if yes, restart monitor EXIT_BRK RTS ; FREEZE BSR INSTAT ;check for key BEQ EXIT_FREZ ;return if none hit BSR CHAR_IN ;get key CMPI.B #$13,D1 ;Control-S? BEQ HOLD_IT BRA TEST_KEY2 ;Control-C? EXIT_FREZ RTS HOLD_IT BSR INSTAT ;wait for another key BEQ HOLD_IT BRA TEST_KEY ;let PANIC check for Control-C ; UPPER_CASE CMPI.B #'a',D1 ;check for lower case BMI NO_CHG CMPI.B #'z'+1,D1 ;first code after 'z' BPL NO_CHG ANDI.B #$DF,D1 ;switch to upper case NO_CHG RTS ; GETLINE MOVEA.L A6,A5 ;copy pointer GETLINE2 MOVEA.L A5,A6 ;reset pointer and CLR.B D6 ;counter for scraped lines GET_CHARS BSR CHAR_IN ;get character CMPI.B #$0D,D1 ;CR ends get line BEQ EXIT CMPI.B #$08,D1 ;back space key and the BEQ BKSPS ;delete key are CHECK_DELETE CMPI.B #$7F,D1 ;back space keys BEQ BKSPS CMPI.B #$15,D1 ;check for ^U and scrap the BEQ LINE_REDO ;line if encountered MOVE.B D1,(A6)+ ;otherwise place character ADDQ.B #1,D6 ;in buffer, update counter and BSR CHAR_OUT ;echo it to the screen BRA GET_CHARS ;get another character EXIT MOVE.B D1,(A6) ;on exit place $0D in buffer and ADDQ.B #1,D6 ;count it BSR CRLF RTS LINE_REDO BSR CRLF ;clean up the screen BRA GETLINE2 ;start over BKSPS CMPI.B #0,D6 BEQ GET_CHARS SUBQ.B #1,D6 SUBA.L #1,A6 MOVE.B #8,D1 BSR CHAR_OUT MOVE.B #' ',D1 BSR CHAR_OUT MOVE.B #8,D1 BSR CHAR_OUT BRA GET_CHARS ; SKIP_BLK CMPI.B #' ',(A6) BNE EXIT_SKIP ADDA.L #1,A6 BRA SKIP_BLK EXIT_SKIP RTS ; BUS_ERROR MOVEA.L #MSG_1,A3 BRA REPORT ADRS_ERROR MOVEA.L #MSG_2,A3 BRA REPORT ILLEGAL_INST MOVEA.L #MSG_3,A3 BRA REPORT DIV_ZERO MOVEA.L #MSG_4,A3 BRA REPORT TRAP_V MOVEA.L #MSG_5,A3 BRA REPORT LEVEL_7 MOVEA.L #MSG_6,A3 BRA REPORT TO_CHAR_IN BSR CHAR_IN RTE TO_CHAR_OUT BSR CHAR_OUT RTE TO_CRLF BSR CRLF RTE TO_PRINT_MSG BSR PRINT_MSG RTE TO_PRINT_BYTE BSR PRINT_BYTE RTE TO_PRINT_WORD BSR PRINT_WORD RTE TO_PRINT_LONG BSR PRINT_LONG RTE TO_GET_BYTE BSR GET_BYTE_T RTE TO_GET_ADDR BSR GET_ADDR_T RTE HELP MOVEA.L #H_MSG1,A3 REPORT BSR CRLF ;new line thank you BSR PRINT_MSG ;print message pointed to by A3 BSR CRLF BRA GETCMD MSG_1 DC.B 'Bus Error',0 MSG_2 DC.B 'Address Error',0 MSG_3 DC.B 'Illegal Instruction Error',0 MSG_4 DC.B 'Divide by Zero Error',0 MSG_5 DC.B 'TRAPV Overflow',0 MSG_6 DC.B 'Level-7 Interrupt',0 HELLO DC.B $0D,$0A ;newline DC.B '68000 Monitor, Version 7.5, C1995 JLACD' DC.B $0D,$0A,0 ;newline and end characters H_MSG1 DC.B $0D,$0A,$0D,$0A DC.B '*** 68000 Cpu-based Single Board Computer ***' DC.B $0D,$0A DC.B 'Command Syntax Action' DC.B $0D,$0A,$0D,$0A DC.B 'DUMP 400 44F Display memory contents' DC.B $0D,$0A DC.B ' Ctrl-S freezes display' DC.B $0D,$0A DC.B ' Any key restarts display' DC.B $0D,$0A DC.B ' Ctrl-C cancels dump' DC.B $0D,$0A,$0D,$0A DC.B 'EDIT 8000 Load RAM starting at 8000' DC.B $0D,$0A DC.B ' Use CR or blank to keep data' DC.B $0D,$0A DC.B ' Ctrl-C cancels patching' DC.B $0D,$0A,$0D,$0A DC.B 'GO 8000 Execute program at 8000' DC.B $0D,$0A,$0D,$0A DC.B 'MOVE 8000 80FF 8100 Move memory contents' DC.B $0D,$0A,$0D,$0A DC.B 'All commands may be shortened to single letters.' DC.B $0D,$0A DC.B 'Use D, E, G, M, or H. Lower case characters' DC.B $0D,$0A DC.B 'as well.' DC.B $0D,$0A,$0D,$0A DC.B 'This 68000 system was designed and programmed by' DC.B $0D,$0A DC.B 'James Antonakos, Alan Dixon and Donovan McCarty.' DC.B $0D,$0A,0 END START