Renesas R5S72621 User Manual

 
Section 23   CD-ROM Decoder 

Page 1252 of 2108 

 

R01UH0134EJ0400  Rev. 4.00 

 

 Sep 

24, 

2014 

SH7262 Group, SH7264 Group

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. 

Figure 23.16 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

End of automatic buffering setup

Set both the CBUF_AUT and 

CBUF_EN bits in CBUFCTL0 to 1

Set both the SUBC_EN and 

CROM_EN bits in CROMEN to 1

Set CBUFCTL1

Set CBUFCTL2

Set CBUFCTL3

[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.

[1]

[2]

[3]

[4]

[5]