Post by thread:[PIC]: Routine for AT45D161 Flash using PIC

Does anyone here have experience with the AT45xx Flash Memory device ? The following code is what I have written to write and read to memory using an absolute address. It does not function. The spi_write routines work on other devices. // *** AT45D161 Memory Routines *** // format is cccccccc rrpppppp ppppppaa aaaaaaaa // cccccccc = command,rr = reserved,pppppppppppp = page address,aaaaaaaaaa = byte location on page // page size is 528 bytes void AT45D161_Write(long abs_address,char Flash_Data) { unsigned int page; unsigned int location; page = ((unsigned int) (abs_address / 528)) << 2; // page address into 2 bytyes and shift left 2 location = (unsigned int) abs_address % 528; // byte address and store in integer AT45D161_EN = false; // select AT45D161 using CE Bit_Delay; // allow > 280ns settling time for CE cDummy = spi_io(ABS_WRITE_CMD); // issue write cmd (0x82) cDummy = spi_io(hi_byte(page)); // 6 MSB of page cDummy = spi_io(lo_byte(page)|hi_byte(location)); // 6 LSB of page and 2 MSB of byte location cDummy = spi_io(lo_byte(location)); // 8 LSB of byte location cDummy = spi_io(Flash_Data); // write data AT45D161_EN = true; // de-select AT45D161 } // format for read is cccccccc rrpppppp ppppppaa aaaaaaaa xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx dddddddd // cccccccc = command,rr = reserved,pppppppppppp = page address,aaaaaaaaaa = address // xxxxxxx ... = Don't care,dddddddd = read data char AT45D161_Read(long abs_address) { unsigned int page; unsigned int location; page = (unsigned int) (abs_address / 528)<<2; // store page address into 2 bytyes and shift left 2 location = (unsigned int) abs_address % 528; // calculate byte address and store in integer AT45D161_EN = false; // select AT45D161 using CE Bit_Delay; // allow > 280ns settling time for CE cDummy = spi_io(READ_CMD); // issue write cmd (0x52) cDummy = spi_io(hi_byte(page)); // send 6 MSB of page cDummy = spi_io(lo_byte(page)|hi_byte(location)); // 6 LSB of page and 2 MSB of byte location cDummy = spi_io(lo_byte(location)); // 8 LSB of byte location cDummy = spi_io(NULL); // 0x00 - ie. Don't care byte cDummy = spi_io(NULL); // 0x00 - ie. Don't care byte cDummy = spi_io(NULL); // 0x00 - ie. Don't care byte cDummy = spi_io(NULL); // 0x00 - ie. Don't care byte cDummy = spi_io(NULL); // read data AT45D161_EN = true; // de-select AT45D161 return (cDummy); // pass read data back to main program } regards David Huisman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.