Renesas R5S72621 User Manual

Page of 2152
 
Section 23   CD-ROM Decoder 
R01UH0134EJ0400  Rev. 4.00  
 
Page 1193 of 2108 
Sep 24, 2014 
 
 
 
SH7262 Group, SH7264 Group 
23.2
 
Block Diagrams 
Figure 23.2 is a block diagram of the CD-ROM decoder functions of this LSI and the bus bridge 
for connection to the bus, that is, of the elements required to implement the CD-ROM decoder 
function. 
Bus bridge
Interrupt and direct memory access controller activation control
Interrupt controller, direct memory access controller
Register data
Stream data
Stream data
Stream data input control
Stream data output control
Descrambler
EDC
EDC
Sync code 
detection/
maintenance
Mode 
determination
Syndrome 
calculator
Core of CD-ROM decoder
Memory 
(2 buffers for ECC)
Memory 
control
ECC control
Timing 
generation
Internal bus
 
Figure 23.2   Block Diagram 
The core of the CD-ROM decoder executes a series of processing required for CD-ROM 
decoding, including descrambling, sync code detection, ECC correction (P- and Q-parity-based 
correction), and EDC checking. The core includes sufficient memory to hold two sectors.