Renesas SH7264 User Manual
Section 23 CD-ROM Decoder
R01UH0134EJ0400 Rev. 4.00
Page 1253 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
(2) Setting Up Manual Buffering
Figure 23.17 shows an example of setting up manual buffering. Each time an ISEC interrupt is
generated, the software checks whether or not the sector is the target sector and starts buffering
when the target sector is found.
generated, the software checks whether or not the sector is the target sector and starts buffering
when the target sector is found.
Start of automatic buffering setup
End of automatic buffering setup
Clear both the CBUF_AUT and
CBUF_EN bits in CBUFCTL0 to 0
Set the CBUF_EN bit
in CBUFCTL0 to 1
Generation of an ISEC interrupt
Read HEAD02, etc.
Target sector?
[1] Turn off the automatic buffering function
and disable buffering in the buffer RAM.
[2] Enable subcode processing and CD-ROM decoding.
[3] Start input of the data stream.
[1]
Set both the CBUF_AUT and
CBUF_EN bits in CBUFCTL0 to 1
[2]
[3]
No
Yes
Figure 23.17 Example of Setting Up Manual Buffering