(This is empirical data)

CCR voice cache control register

To fill the cache set CCR_CACHEINVALIDSIZE to 0 and then to
the number of samples you want to load. All cache data registers are
32 bit.
Samples are 8bit for mono/8bit, 16bit for stereo/8bit & mono/16bit
and 32 bit for stereo/16bit.

Samples are read from the voice buffer starting at the CCCA_CURRADDR
position and going down.
Samples are written to the cache data registers (CD0/F) starting at
CD0 + (CCR_READADDRESS - 1) / 2 and going down.

CD0 - 1 = 16 MSB of CDF
CD0 = 16 LSB of CD0
CD0 + 1 = 16 MSB of CD0

Vibrato modulation:

FMMOD_MODVIBRATO	amplitude of the modulation
TREMFRQ_FREQUENCY	frequency of the modulation
