Changes
/* Command Register (W) (A0=1) */
* STOP Mode: Output is silent, REQ is set, next write to Data register will be treated as 8bit Starting Pitch value, to be followed by the 32bit Speech Frame data, thereafter sound output will start (and the device is no longer in STOP Mode).
* After completing a speech frame (which takes 8..64 ms), the CPU can output another speech frame (by writing another 32bit to the data register), if the CPU doesn't supply new data then Slow Stop or Continue will occur (as selected in the Command Register).
* SLOW STOP Mode: After completing the last speech frame, the last frame will be repeated once (with decaying amplitude & same pitch), thereafter, STOP mode is entered.
