cxd2589q Sony Electronics, cxd2589q Datasheet - Page 38

• Manufacturer Part Number: cxd2589q
• Description: Cd Digital Signal Processor
• Manufacturer: Sony Electronics

3. Description of Modes
This LSI has three basic operating modes using a combination of spindle control and the PLL. The operations
for each mode are described below.
3-1. CLV-N Mode
3-2. CLV-W Mode
3-3. CAV-W Mode
This mode is compatible with the CXD2507AQ, and operation is the same as for the conventional control.
The PLL capture range is ±150kHz.
This is the wide capture range mode. This mode allows the PLL to follow the rotational velocity of the disc.
This rotational following control has two types: using the built-in VCO2 or providing an external VCO. The
spindle is the same CLV servo as for the conventional series. Operation using the built-in VCO2 is described
below. (When using an external VCO, input the signal from the VPCO pin to the low-pass filter, use the
output from the low-pass filter as the control voltage for the external VCO, and input the oscillation output
from the VCO to the VCKI pin.)
While starting to rotate a disc and/or speeding up to the lock range from the condition where the disc is
stopped, CAV-W mode should be used. This is because the capture range for CLV-W mode is wider than
the conventional lock range. Concretely, first send $E6650 to set CAV-W mode and kick the disc, then send
$E60C0 to set CLV-W mode when ALOCK is high. Playback is normally performed in CLV-W mode. The
microcomputer monitors the serial data output, and must return the operation to the speed adjusting state
(CAV-W mode) when ALOCK becomes low. The control flow according to the microcomputer software is
shown in Fig. 3-2.
In CLV-W mode (normal), low power consumption is achieved by setting LPWR to high. Control was formerly
performed by applying acceleration and deceleration pulses to the spindle motor. However, when LPWR is
set to high, deceleration pulses are not output, thereby achieving low power consumption mode.
Note) The capture range for CLV-W mode has theoretically the range up to the signal processing limit.
This is CAV mode. In this mode, the external clock is fixed and it is possible to control the spindle to variable
rotational velocity. The rotational velocity is determined by the VP0 to 7 setting values or the external PWM.
When controlling the spindle with VP0 to 7, setting CAV-W mode with the $E6650 command and controlling
VP0 to 7 with the $DX commands allows the rotational velocity to be varied from low-speed to double-speed.
(See the $DX commands.) Also, when controlling the spindle with the external PWM, the PWMI pin is binary
input which becomes KICK during high intervals and BRAKE during low intervals.
The microcomputer can know the rotational velocity using V16M. The reference for the velocity
measurement is a signal of 132.2kHz obtained by 1/128-frequency dividing the crystal (384Fs). The velocity
is obtained by counting V16M/2 pulses while the reference is high, and the result is output from the new CPU
interface as 8bits (VF0 to 7). These measurement results are 31 when the disc is rotating at normal speed or
63 when it is rotating at double speed. These values match those of the 256-n for control with VP0 to 7.
In CAV-W mode, the spindle is set to the desired rotational velocity and the operation speed for the entire
system follows this rotational velocity. Therefore, the cycles for the Fs system clock, PCM data and all other
output signals from this LSI change according to the rotational velocity of the disc (excluding DATO, CLKO
and XLTO).
Note) The capture range for this mode is theoretically up to the signal processing limit.
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CXD2589Q