SAA7348GP Datasheet, PDF (27/60 Pages) NXP Semiconductors – All Compact Disc Engine ACE

Philips Semiconductors
All Compact Disc Engine (ACE)
Preliminary specification
SAA7348GP
8.1.4 SERVO STATUS REGISTER (STR)
The Servo Status Register holds high level status information on the servo system. The information is latched into a
register and cleared whenever the register is read. This information could be a trigger to initiate a recovery. The register
is byte addressable; read only.
Table 15 Servo status register (address 0XE9H)
7
Srv_tl1
6
Srv_tl0
5
4
3
Srv_shock Srv_hf_present Srv_FIFO_ov
2
Srv_fock
1
Srv_otd_inp
0
Srv_subc
Table 16 Description of STR bits
BIT
SYMBOL
DESCRIPTION
7
Srv_tl1
internal servo signal; see Table 17
6
Srv_tl0
internal servo signal; see Table 17
5
Srv_shock shock: decoder status signal; Motstart2 + PLL_phase_lock + Motor-ov + FOCOK +
OTD
4
Srv_hf_present HF_present: internal decoder signal; indicates if laser spot is in a recorded area
3
Srv_FIFO_ov FIFO_OV: decoder status signal; FIFO overflow occurred
2
Srv_fock FOCOK: servo output signal; focus OK/OK
1
Srv_otd_inp OTD: servo output signal; laser spot on/off track
0
Srv_subc subcode found: decoder status signal; subcode present in servo buffer
The Srv_tl0 and Srv_tl1 signals can be used to determine in which direction the servo is counting during a jump
execution.
Table 17 Servo jump modes
Srv_tl1
0
0
1
1
Srv_tl0
0
1
0
1
protected mode
fast jump_1
slow jump
fast jump_2
DESCRIPTION
1997 Jul 11
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