FEDL2215-01
Semiconductor
ML2215
1
8.2 Musical Note Data
Musical note data consists of 2 bytes and is stored in the Mask ROM’s User’s Data area, where a user can define
scale, note and the end-bit for a music phrase. Table 8.2 shows the coding format for musical note data.
Table 8.2 Coding Format for Musical Note Data
NSB
7SB
0
6SB
L5
5SB
L4
4SB
L3
3SB
L2
2SB
L1
LSB
L0
The First Byte END-Bit
Musical Note Code
Musical Scale Code
The Second Byte
N7
N6
N5
N4
N3
N2
N1
N0
(1) Musical Scale Code
Musical scale code is defined at the second byte. The following equation shows output frequency from the Music
Generator circuit at 4.096 MHz external clock.
32
kHz (“N” is integer between 4 to 127)
(N + 2)
Co-relationship between “N” and musical scale can be calculated as follows:
N = 27N7 + 26N6 +25N5 + 24N4 + 23N3 + 22N2 + 21N1 + 20N0
When all values for N7 to N2 are set to “0”, no music is reproduced during the period specified by the note code.
At this instance, the values of N1 and N0 have no significance (Don’t care).
Table 8.3 shows major musical scales (keys) and their corresponding scale codes.
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