LAPIS Semiconductor ML610421, User Manual, Page: 299 / 437

ML610Q421/ML610Q422/ML610421 User’s Manual
Chapter 23 Melody Driver
23 – 9
23.3.3 Tone Length Codes
A tone length code is set in the melody 0 tone length code register (MD0LEN).
Table 23-2 shows the correspondence between tone lengths and tone length codes.
The tone length when all the bits are set to "0" is equal to the shortest tone length (the tone length when the only M0LN0
bit is set to "1").
Table 23-2 Correspondence between Tone Lengths and Tone Length Codes
Tone length
Tone length code (MD0LEN)
M0LN5 M0LN4 M0LN3 M0LN2 M0LN1 M0LN1 M0LN5–0
1 1 1 1 1 1 3FH
1 0 1 1 1 1 2FH
0 1 1 1 1 1 1FH
0 1 0 1 1 1 17H
0 0 1 1 1 1 0FH
0 0 1 0 1 1 0BH
0 0 0 1 1 1 07H
0 0 0 1 0 1 05H
0 0 0 0 1 1 03H
0 0 0 0 1 0 02H
0 0 0 0 0 1 01H
The tone length set by a tone length code and a tempo code is expressed by the following equation.
Tone length = 1.953125
×
( TP + 1 )
×
( LN + 1 ) ms
where TP is an integer of 1 to 15, and LN is an integer of 1 to 63.
The bit correspondence between TP and tempo codes is expressed by the following equation.
TP = 2
3
M0TP3 + 2
2
M0TP2 + 2
1
M0TP1 + 2
0
M0TP0
The bit correspondence between LN and tone length codes is expressed by the following equation.
LN = 2
5
M0LN5 + 2
4
M0LN4 + 2
3
M0LN3 + 2
2
M0LN2 + 2
1
M0LN1 + 2
0
M0LN0