;***************************************************************************** ; MegaSquirt Flash page erase and programming routines by Guy Hill. ; Heavily based on the routines from boot_r12.asm; load into ram ABOVE the ; stack! See init_stack in boot_r12.asm. ; ;***************************************************************************** ;------------------------------------------------------------------------------- ; burnConst: is a PCC compatible FLASH Programming Routine - I think ;------------------------------------------------------------------------------- burnConst: ldhx #ms_rf_start_f sthx burnDst jsr ms_EraseFlash ; Erase the first 128 byte block ldhx burnDst aix #64T aix #64T sthx burnDst jsr ms_EraseFlash ; and the second ldhx #ms_rf_start_f sthx burnDst ldhx #ms_rf_start sthx burnSrc lda #$00 ; burn the lot 256 bytes in all sta burncount clrh clrx jmp ms_ProgramFlash burnByte: ; byte to be burnt on stack, together with destination address ; Stack ; byte ; dest low ; dest high ; pula sta tmp21 ldhx #tmp21 sthx burnSrc pulx pulh sthx burnDst lda #$01 ; burn 1 byte sta burncount jmp ms_ProgramFlash ;------------------------------------------------------------------------------- ;* Single Flash Page Erase Subroutine ====================================== ;* ; This subroutine will copy the Flash Erase algorithm into RAM and execute ; it to erase the page starting at address pointers "burnDst" ; ms_EraseFlash: ldhx #ms_EraseRamSize ; initialize pointer ms_EraseFlash1: lda ms_MassErase-1,x ; get program from Flash sta ram_exec-1,x ; copy into RAM dbnzx ms_EraseFlash1 ; decrement pointer and loop back until done jmp ram_exec ; execute Flash Mass Erase algorithm from RAM ;* Flash Program Subroutine ================================================ ;* ; This subroutine will copy the Flash Program algorithm into RAM and execute it ; to program 'burncount' bytes from the address pointed to by 'burnSrc' to the ; address pointed to by "burnDst" ; ms_ProgramFlash: ldhx #ms_ProgramRamSize ; initialize pointer ms_ProgramFlash1: lda ms_Delay-1,x ; get program from Flash sta ram_exec-1,x ; copy into RAM dbnzx ms_ProgramFlash1 ; decrement pointer and loop back until done jmp {ram_exec+ms_ProgramRam} ; ; ;* Flash Erase Subroutine ================================================== ;* ;* This subroutine performs a single Page Erase @ BurnDst ;* This subroutine has been ;* tuned for a bus speed of 7.3728 MHz. ;* This subroutine is copied into and executed from RAM. ;* ms_MassErase: ldhx burnDst ; initialize pointer to Flash memory address ; Set ERASE, read the Flash Block Protect Register and write any data into Flash page. ; lda #{ERASE} ; set ERASE control bit sta flcr ; in Flash Control Register lda flbpr ; read from Flash Block Protect Register sta ,x ; write any data to address within page ; ; Wait for >10us, then set HVEN. ; lda #1 ; wait bsr ms_delay ; for 11.7us lda #{ERASE | HVEN} ; set HVEN control bit sta flcr ; in Flash Control Register ; ; Wait for >1ms, then clear ERASE. ; lda #100T ; wait bsr ms_delay ; for 1.005ms lda #{HVEN} ; clear ERASE control bit sta flcr ; in Flash Control Register ; ; Wait for >5us, then clear HVEN. ; lda #1 ; wait bsr ms_delay ; for 11.7us clra ; clear HVEN control bit sta flcr ; in Flash Control Register rts ; return ;* Delay Subroutine ======================================================================= ;* ;* This subroutine performs a simple software delay loop based upon the value passed in ACC. ;* The following timing calculation applies: ;* ;* delay = ((ACC * 74) + 12) (tcyc) ;* ;* Calling convention: ;* ;* lda data ;* jsr delay ;* ;* Returns: nothing ;* ;* Changes: ACC ;* ms_Delay: psha ; [2] save outer delay loop parameter ms_Delay1: lda #22 ; [2] initialize inner delay loop counter ms_Delay2: dbnza ms_Delay2 ; [3] decrement inner delay loop counter dbnz 1,sp,ms_Delay1 ; [6] decrement outer delay loop counter pula ; [2] deallocate local variable rts ; [4] return ms_EraseRamSize: equ {*-ms_MassErase} ms_ProgramRam: equ {*-ms_Delay} ;* Flash Program Subroutine =============================================================== ;* ;* This subroutine controls the Flash programming sequence. ms_FlashProgram: ms_FlashProgram1: ; Set PGM, read the Flash Block Protect Register and write anywhere in desired Flash row. ; lda #{PGM} ; set PGM control bit sta flcr ; in Flash Control Register lda flbpr ; read from Flash Block Protect Register ldhx burnDst sta ,x ; write any data to first Flash address ; ; Wait for >10us, then set HVEN. lda #1 ; wait bsr ms_delay ; for 11.7us lda #{PGM | HVEN} ; set HVEN control bit sta flcr ; in Flash Control Register ; ; Wait for >5us. lda #1 ; wait bsr ms_delay ; for 11.7us ; ; Write data to Flash and wait for 30 - 40us. ldhx burnsrc lda ,x ; get data byte ldhx burndst sta ,x ; write data to Flash lda #3 ; wait bsr ms_delay ; for 31.7us ; ; Clear PGM. lda #{HVEN} ; clear PGM sta flcr ; in Flash Control Register ; ; Wait for >5us, then clear HVEN. lda #1 ; wait bsr ms_delay ; for 11.7us clra ; clear HVEN control bit sta flcr ; in Flash Control Register ; ; Advance destination pointer and decrement data counter. ; ms_FlashProgram2: ldhx burnsrc aix #1 ; advance source pointer sthx BurnSrc ldhx burndst aix #1 ; advance destination pointer sthx BurnDst dbnz burncount,ms_FlashProgram1 ; decrement counter and loop ; back if not done. rts ; return ms_ProgramRamSize equ {*-ms_Delay} ; Make sure the constant on the next line is the same as ; ram_exec in boot_r12.asm.equ. ms_ProgramLastRam equ {$01ED+ms_ProgramRamSize-1}