Winbond W56964

A [https://engineering.purdue.edu/ece477/Webs/F06-Grp04/Datasheets%20sept24/W56964%20Docs/Document/DesignGuide/W56964%20CPU%20interface%20and%20registers%20rev.%20A1.pdf datasheet] is available in a Purdue University [https://engineering.purdue.edu/ece477/Webs/F06-Grp04/index.html project report]. It is a bit discouraging that they apparently didn't get it to work.

There used to be application notes in [http://www.google.com/#q=W569+site:uglyduck.ath.cx Google's cache]. That [http://www.google.com/#q=CCChien0+site:uglyduck.ath.cx page] also had what Winbond calls ''middleware'', i.e., the driver.

Sunplus SPMA100B
No datasheet available and registers are different although the chip is pin-compatible to the above. Traces generated with the original firmware and register dumps during operation suggest:

{{{
#define SPMA_SEQUENCER_FIFO 0xc5
#define SPMA_SEQUENCER_SPACE 0xc7 // decreases with every written byte

#define SPMA_SEQUENCER_STATUS 0xd6
#define SPMA_SEQ_FIFO_EMPTY 0x80
#define SPMA_SEQ_FINISHED 0x40
#define SPMA_SEQ_FAILED 0x20

0xe1
Power controls. No sound or clicks if sequence (0xff -> 0x7e -> 0x1e -> 0x04 -> 0x00) is wrong.

0xe3 ... 0xe6
Volume registers where 0=Mute, 1=-30dB ... 31=0dB in 1dB steps (equal to W56964)
}}}

Macronix MX92U832AZCG

Seems to be a product of [http://www.modiotek.com.tw/ Modiotek]. No further information available.

OKI ML2864

The [http://read.pudn.com/downloads119/sourcecode/others/505180/SRTP/documents/datasheet/ML2864_000002_E.pdf datasheet] explains the concepts a bit more detailed. The ''Exclusive Format'' might solve the mystery of the data send to the SPMA100B.