MSP430 audio output

SD card data layout

SD card storage is divided into 512 byte chunks called sectors. A full 512 byte sector must be read or written at once. The MSP430F2013 has only 128 bytes of RAM -- too little memory to hold a whole sector for random access. However, we can still read/write each byte in order, as it's needed. As long as each byte is read or written sequentially, this method will suffice.