Re: Flash erase byte routine
bit more of an attempt , steve can you check the logic ,cleanup ,
Code:Flash_Byte_Modify: ' assumes address , length ( upto 256bytes ) ' assumes sector 0 is not protected ' assumes selectted sector is not protected Flash_Addr_Copy.byte3 = Data_Length ' save the selected address & length Flash_Addr_Copy.byte2 = SDC_Sector Flash_Addr_Copy.byte1 = SDC_Page Flash_Addr_Copy.byte0 = SDC_Byte SDC_sector = 0 gosub Flash_Sec_Erase ' erase sector 0 SDC_sector = 0 ' use sector 0,instead of given sector , but use given page, byte length gosub Flash_write ' Write the the changed data to sector 0 if Flash_Addr_Copy.byte1 = 0 then ' find the pages to copy - copy all pages/ bytes above 0 for given sector for SDC_Page = 1 to 255 ' read all pages above 0 of selected sector SDC_Sector = Flash_Addr_Copy.byte2 ' of read selected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Read ' read 255 bytes at a time SDC_Sector = 0 ' use sector 0 aselected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Write ' write next SDC_Page endif if Flash_Addr_Copy.byte1 = 255 then ' find the pages to copy - copy all pages/ bytes below given page/ byte of sector for SDC_Page = 0 to 254 ' read all pages below 255 of selected sector SDC_Sector = Flash_Addr_Copy.byte2 ' of read selected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Read ' read 255 bytes at a time SDC_Sector = 0 ' use sector 0 aselected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Write ' write next SDC_Page endif if Flash_Addr_Copy.byte1 >0 and Flash_Addr_Copy.byte1 < 254 then ' find the pages to copy - copy all pages/ bytes below given page/ byte of sector for SDC_Page = 0 to Flash_Addr_Copy.byte1 - 1 ' read all pages from 0 to selected page -1 SDC_Sector = Flash_Addr_Copy.byte2 ' of read selected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Read ' read 255 bytes at a time SDC_Sector = 0 ' use sector 0 aselected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Write ' write next SDC_Page endif for SDC_Page = Flash_Addr_Copy.byte1 + 1 to 255 ' read all pages from selected page + 1 to 255 SDC_Sector = Flash_Addr_Copy.byte2 ' of read selected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Read ' read 255 bytes at a time SDC_Sector = 0 ' use sector 0 aselected sector SDC_byte = 0 ' bytes 0 - 255 Data_Length = 255 ' all bytes gosub Flash_Write ' write next SDC_Page endif endif if Flash_Addr_Copy.byte0 + Flash_Addr_Copy.byte3 < 255 then ' if the start byte + data length of the data changed is < 255 bytes , ' then copy bytes below the selected changed data SDC_Sector = Flash_Addr_Copy.byte2 ' read selected sector SDC_PAGE = Flash_Addr_Copy.byte1 ' of selected page SDC_byte = 0 ' start address bytes 0 to Data_Length = Flash_Addr_Copy.byte0 - 1 ' selected byte - 1 ( length) gosub Flash_Read ' read SDC_Sector = 0 ' use sector 0 aselected sector SDC_PAGE = Flash_Addr_Copy.byte1 ' of selected page SDC_byte = 0 ' start address bytes 0 to Data_Length = Flash_Addr_Copy.byte0 - 1 ' selected byte - 1 ( length) gosub Flash_Write ' write ' then copy bytes above the selected changed data SDC_Sector = Flash_Addr_Copy.byte2 ' read selected sector SDC_PAGE = Flash_Addr_Copy.byte1 ' of selected page SDC_byte = Flash_Addr_Copy.byte0 + Flash_Addr_Copy.byte3 ' start address bytes above given address and length Data_Length = 255 - SDC_byte ' data above changed bytes ( length = 255 bytes - given addrees + given length ) gosub Flash_Read ' read the data SDC_Sector = 0 ' use sector 0 SDC_PAGE = Flash_Addr_Copy.byte1 ' of selected page SDC_byte = Flash_Addr_Copy.byte0 + Flash_Addr_Copy.byte3 ' start address bytes above given address and length Data_Length = 255 - SDC_byte ' data above changed bytes ( length = 255 bytes - given addrees + given length ) gosub Flash_Write ' write the data endif ' Sector 0 should now have a complete copy of the data + changed data from the orginal selected sector SDC_sector = Flash_Addr_Copy.byte2 gosub Flash_Sec_Erase ' erase orginal sector for SDC_PAGE = 0 to 255 ' copy sector 0 pages to selected sector 0 ( 256bytes at a time) SDC_Sector = 0 ' use sector 0 SDC_byte = 0 Data_Length = 255 gosub Flash_Read ' read the data SDC_Sector = Flash_Addr_Copy.byte2 ' use selected sector SDC_byte = 0 Data_Length = 255 next SDC_PAGE SDC_sector = 0 ' clean up sector 0 gosub Flash_Sec_Erase ' erase orginal sector return
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