Renesas R5S72621 User Manual

 
Section 23   CD-ROM Decoder 

Page 1258 of 2108 

 

R01UH0134EJ0400  Rev. 4.00 

 

 Sep 

24, 

2014 

SH7262 Group, SH7264 Group

When reading of the stream data is slower than writing of the stream data, the buffer of the CD-
ROM decoder will overflow. This causes the CD-ROM decoder to be abnormally stopped. 
Caution is required in writing and reading of the stream data. Sample combinations of stream data 
transfer settings are shown below. 

LW/cycle-stealing transfer by 
direct memory access controller 
(without padding) 

(1) 16-byte/cycle-stealing transfer by direct memory access 

controller (16 bytes*) 

(2) Burst transfer by direct memory access controller (16 bytes*, 

longword, word) 

LW/cycle-stealing transfer by 
direct memory access controller 
(with padding) 

(1) Cycle-stealing transfer by direct memory access controller 

(16 bytes*, longword) 

(2) Burst transfer by direct memory access controller (16 bytes*, 

longword, word) 

LW write by CPU 

(1) Cycle-stealing transfer by direct memory access controller 

(16 bytes*, longword, word) 

(2) Burst transfer by direct memory access controller (16 bytes*, 

longword, word) 

Note:  *  Set bit 25 in the DMA channel control register (CHCR_n) to 1, as well as making the 

regular settings for 16-byte transfer. 

 

When reading the stream data, be sure to use either the direct memory access controller or the 
CPU. If both the direct memory access controller and the CPU are used for reading, the stream 
data may not be recognized as being in the CD-ROM format.