Renesas R5S72621 User Manual
Section 23 CD-ROM Decoder
Page 1256 of 2108
R01UH0134EJ0400 Rev. 4.00
Sep
24,
2014
SH7262 Group, SH7264 Group
23.5.2
Timing of Status Registers Updates
The status information registers of the CD-ROM decoder are updated on each ISEC interrupt. The
sector for which information is reflected in the status registers is selected by the ER0SEL bit of the
CROMCTL4 register.
sector for which information is reflected in the status registers is selected by the ER0SEL bit of the
CROMCTL4 register.
23.6
Usage Notes
23.6.1
Stopping and Resuming Buffering Alone during Decoding
When the data of the output stream are being not read out but operation of the CD-ROM decoder
has continued until the buffers are full, the BUF_NG bit in the CBUFST2 register is set to 1; after
that, the CD-ROM decoder becomes incapable of operation.
has continued until the buffers are full, the BUF_NG bit in the CBUFST2 register is set to 1; after
that, the CD-ROM decoder becomes incapable of operation.
To stop buffering alone, clear the CBUF_EN bit in the CBUFCTL0 register to 0. If the automatic
buffering function is in use, clear the CBUF_AUT in the CBUFCTL0 register to 0 at the same
time. In this case, the sectors currently in the buffers must be read out.
buffering function is in use, clear the CBUF_AUT in the CBUFCTL0 register to 0 at the same
time. In this case, the sectors currently in the buffers must be read out.
To resume automatic buffering, set the CBUF_AUT and CBUF_EN bits in the CBUFCTL0
register at the same time.
register at the same time.
23.6.2
When CROMST0 Status Register Bits are Set
1. When the ST_SECS bit in the CROMST0 register becomes set, stop decoding immediately
and retry from one sector before the sector that was being decoded.
2. When the ST_SECL bit in the CROMST0 register becomes set, stop decoding immediately
and retry from two sectors before the sector that was being decoded.