(A more readable version of this will be handed out.)

	Binary Note Code	Decimal Period Length (Clock Pulses)	Hexidecimal Period Length (Clock Pulses)
C	0000	4095	FFF
C#	0001	3865	F19
D	0010	3648	E40
D#	0011	3443	D73
E	0100	3250	CB2
F	0101	3068	BFC
F#	0110	2896	B50
G	0111	2733	AAD
G#	1000	2580	A14
A	1001	2435	983
A#	1010	2298	8FA
B	1011	2169	879

The CLK line in the waveforms above is solid black. This is because the clock pulses are very close together.

The first INCNT pulse occurs at the extreme left of the waveforms above. Because INCNT occurs on the leading edge of PERIOD_IN, the Input Counter starts counting when it sees INCNT go high. The Input Counter stops counting when PERIOD_IN goes low. Thus, the Input Counter finishes up with a number representative of the period length. Other PERIOD_IN pulses are ignored until the entire cycle (LD_STHO, LD_ND, LATCH_OUT_PER, and CYCLE_END) has finished. Then, the next time PERIOD_IN goes high, a new INCNT pulse is generated, and a new cycle is begun.

Notice that for the first cycle, the Input Counter (QINPONE) reaches 22H. When the first LD_ND pulse comes along, the Note Determiner circuit puts 0BH onto the note select lines (NOTESEL). This is the correct value for an input period of 22H, as can be seen from the table on the left above. (The Note Determiner counts down from 22H until it reaches 21H, which corresponds to 0BH, which also happens to be the note B.)

When the second LD_ND pulse comes along, QINPONE contains 21H. The Note Determiner also converts this into a note select code of 0BH.

When the third LD_ND pulse comes along, QINPONE contains 30H. The Note Determiner counts down from this until it reaches 2FH. From the table on the left above, you can see that this corresponds to a note code of 05H, which is the code for the note F.

When the fourth LD_ND pulse comes along, QINPONE also contains 30H, and the Note Determiner also puts out a note code of 05H.

The Note to 12-Bit Period circuit takes the 0BH note code and converts it to 879H. The table on the right above shows that this is the correct period length for the note B.

The Note to 12-Bit Period circuit takes the 05H note code and converts it to 0BFCH, which is the corect period length for the note F.

For some reason, the note code at the far left of the waveforms is 8, and the Note Determiner circuit converts this to a period length of 0A10H. The note code 8 corresponds to the note G#, which should be 0A14H, as can be seen from the table on the right above. At present, I can't see why this happens. Hopefully, it's has something to do with the fact that the tone translator circuit has just started up.