SAA7382GP Philips Semiconductors, SAA7382GP Datasheet - Page 17

• Manufacturer Part Number: SAA7382GP
• Description: Error correction and host interface IC for CD-ROM ELM
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Table 7 Error correction modes
Note
1. Where X = don’t care.
7.7.13
The reset function clears all the flags in this register.
Table 8 CTRL1 register bits
1996 Apr 25
Error correction and host interface IC for
CD-ROM (ELM)
DECEN
BIT
0
1
1
1
1
1
1
7
6
5
4
3
2
1
0
CTRL1
lookahead
COWREN
FORMRQ
MBCKRQ
DSCREN
SHDREN
MODRQ
SYDEN
NAME
SYIEN
X
0
0
0
0
1
1
Disable sync interpolation = 0; Enable sync interpolation = 1. Enabling SYIEN prevents
loss of synchronization when an error occurs in a sync pattern during data read.
Disable sync detection = 0; Enable sync detection = 1. Enabling SYDEN synchronizes
the decoder with the sync pattern detected in the input data.
Descramble disable (audio) = 0; Descramble enable = 1. This bit enables/disables
descrambling. Setting this bit to logic 0 allows reading of raw data on disc, even audio
signals. This bit should be set to logic 1 for CROM data.
CRC with error correction disabled = 0; Detection errors are corrected = 1. This bit
enables/disables rewriting of error bytes in the buffer during error correction. Setting
the bit to logic 0 allows CRC checks without error correction.
Mode 1 request = 0; Mode 2 request = 1. This bit discriminates Mode 1/Mode 2.
Form 1 request = 0; Form 2 request = 1. This bit discriminates Mode 2/Form 1 and
Mode 2/Form 2.
Disable mode check function = 0; Enable mode check function = 1. If the mode
specified in the mode byte does not correspond with the raw data mode bit and this bit
is set to logic 1 then error correction and detection is disabled.
Header data on registers Head0 to Head3 = 0; Sub-header data on registers
Head0 to Head3 = 1. This bit toggles header and sub-header data between registers
HEAD0 to HEAD3.
WRRQ
X
0
0
1
1
1
1
ECCRQ
X
0
1
0
1
0
1
17
decoder disable; note 1
monitor only
repeat correction
write only
real-time correct, normal mode
write only, lookahead
real-time correct, lookahead
FUNCTION
decoder mode
Preliminary specification
SAA7382