SH7263 Datasheet, PDF (1176/1862 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 21 CD-ROM Decoder (ROM-DEC)
21.4.6 Target-Sector Buffering Function
In the CD-ROM decoder, the sector for output can be designated in two ways: automatic
buffering, where the CD-ROM decoder itself detects the presence of target sectors, and manual
buffering, where the target sector for output is designated by software and the software also
recognizes the sectors buffered in the CD-ROM decoder.
The following describes the procedures for setting the registers in the CD-ROM decoder to set up
automatic or manual buffering.
(1) Setting Up Automatic Buffering
Figure 21.16 shows an example of setting up the automatic buffering. Set the relevant CD-ROM
decoder registers and start input of the data stream; the CD-ROM decoder then detects the target
sector and starts the output of the stream data.
Start of automatic buffering setup
Set both the CBUF_AUT and
CBUF_EN bits in CBUFCTL0 to 1 ^[1]
Set CBUFCTL1
[2]
Set CBUFCTL2
[3]
Set CBUFCTL3
[4]
[1] Turn on the automatic buffering function and
enable buffering in the buffer RAM.
[2] Set the minutes value of the target sector.
[3] Set the seconds value of the target sector.
[4] Set the frame value of the target sector.
[5] Enable subcode processing and CD-ROM decoding.
Set both the SUBC_EN and
CROM_EN bits in CROMEN to 1 ^[5]
End of automatic buffering setup
Figure 21.16 Example of Setting Up Automatic Buffering
Rev. 2.00 Mar. 14, 2008 Page 1142 of 1824
REJ09B0290-0200