Section 23 CD-ROM Decoder
R01UH0134EJ0400 Rev. 4.00 Page 1203 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
Bit Bit Name
Initial
Value R/W Description
6 0 R/W Reserved
This bit is always read as 0. The write value should
always be 0.
5 MD_AUTO 0 R/W Automatic Mode/Form Detection ON/OFF
0: OFF
1: ON
Detectable formats are Mode 0, Mode 1, Mode 2 (non-
XA), Mode 2 Form 1, and Mode 2 Form 2. If the mode
and form cannot be detected, the sector is taken to be
in the same mode and form as the previous sector. If
the mode and form of the first sector after decoding
starts is undetectable, the setting of the MD_SEC[2:0]
bits is used as the initial value.
4 MD_
AUTOS1
0 R/W Criteria for Mode Determination when MD_AUTO = 1
0: Mode determination is made only when the sync
code is detected
1: Mode determination is always made
The setting of this bit is valid only when the MD_AUTO
bit is 1. If the mode cannot be determined, the mode of
the previous sector is used. When this bit is cleared to
0, mode determination is made only when the sync
code is detected for the sector.
3 MD_
AUTOS2
0 R/W Criteria for Mode 2 Form Determination when
MD_AUTO = 1
0: The sector is assumed to be non-XA if the two form
code bytes in the subheader do not match
1: No determination of XA or non-XA for the sector. The
first form byte is regarded as valid. However, the two
form bytes are compared, and the result is reflected
in a status bit.
The setting of this bit is valid only when the MD_AUTO
bit is 1.