MN66279RSC Datasheet, PDF (61/96 Pages) Panasonic Semiconductor – LSI FOR COMPACT DISC/CD ROM PLAYER

MN662790RSC
7-2 (4) Subcode interface
A. Read SUBQ data
You can read subcode data in two ways according to the setting of the SSEL pin. The timing is shown in
Figure 7-2-5.
When SSEL=L:
When SSEL pin is at L level, this LSI and the microcomputer serve as master and slave, respectively, to
read SUBQ data. BLKCK and CLDCK are output at fixed frequencies of 75 Hz and 7.35 kHz,
respectively. SUBQ output varies in synchronization with the falling edge of CLDCK output.
The microcomputer receives SUBQ output at the timing of the rising edge of CLDCK output. If the CRC
output is OK, it is processed as correct data. The result of CRC check can be read by CRC or STAT pin.
The content of SUBQ is output as follows: S0 and S1 signals are output in synchronization with BLKCK
output. Then, 80-bit subcode data are output. Then 8-bit peak detection data on the left or right channel is
output twice continuously. When SSEL=L, SUBQ output is inverse one.
When SSEL=H:
When SSEL pin is at H level, this LSI and the microcomputer serve as slave and master, respectively, to
read SUBQ data. The LSI receives an output signal from the microcomputer regardless of CLDCK output,
and changes SUBQ output. Then, by entering 96 clocks of SQCK, all SUBQ output can be read.
The microcomputer starts the interrupt operation at the rising edge of BLKCK output. First, it checks the
result of CRC of SUBQ output. If it is OK, SQCK is input to read SUBQ data.
The contents of SUBQ are synchronized with the rising edge of BLKCK. First, a CRC result is output,
and then, 80-bit subcode data are output every falling edge of SQCK. Then 8-bit peak detection data on the
left or right channel is output twice continuously. At SSEL = H, SUBQ output is positive one.
By inputting the microcomputer command 000847h as shown in Table 7-1-4 (6), subcode data in the unit
of byte is output beginning with the LSB at every falling edge of SQCK.
Read subcode data from STAT with command
By inputting the microcomputer command 78H as shown in Table 7-1-4 (11), subcode data can be read
from STAT pin in synchronization with the falling edge of MCLK on condition that the SSEL pin is at H
level. This mode is available only immediately after issuance of the microcomputer command 78h. This
mode is cancelled when other commands are issued.
SDD00025AEM
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