Philips CDR Mozart Service Manual page 51

9.4.2 Supply
Mozart is supplied with 3V3 and 2V5 voltages. The regulators
7208 and 7209 ensure these voltages.
96MHz(EMUL_PSTCLK) 96MHz(EMUL_PSTCLK)
SRAM
96MHz
Core
P
2.5V
A
D
3.3V
MOZART
Figure 9-2
9.4.3 Reset
The reset line is active at low voltage. The reset signal comes
from the display uP (pos 7005 is not mounted).
SIGNAL
Figure 9-3
9.4.4 VCXO
Mozart needs an external clock of 33.8688 MHz (pos 1005).
Internal PLL can convert the processor clock to 96MHz.
All peripherals of Mozart run at the half processor clock rate
(48MHz).
To protect against buffer over- and underflow during external
digital recording, the 33.8688 MHz must be adaptable with +/
- 150ppm. Therefore the clock is designed as a VCXO
(Voltage Controlled X-tal Oscillator). Varicaps 6002 and 6003
change their capacity value when the outputs of 7002 differ
the DC voltage. Change of the capacity load of the X-tal
changes the output frequency of the X-tal.
Output X-TRIM of Mozart is a PDM (Pulse Density
Modulation) signal (from 0 to 100% Duty Cycle). Opamp
7002 converts this signal into a DC voltage that drives the
varicaps. That voltage can vary from 0V to 12V DC.
48MHz(BCLK)
16.9MHz
PLL
2.5V
33.868MHz
Crystal
P
A
D
3.3V
CL 16532046_026.eps
040701
CL 16532046_027.eps
040701
Circuit Description
9.4.5 Clock Output
CL16 is a clock output of Mozart. The frequency half the X-
tal frequency (16MHz). This signal is buffered through 7010.
Outputs of this buffer go to DAC and ADC as Master clock.
Mozart also delivers the system clock for the CDR device.
FREYA needs an 8MHz clock and RACOON needs a 16MHz
clock. Clock division is done by flip-flop 7004. NAND port
7012 is driven by EMUL_PST1. This circuitry switches
between the 8 and 126 MHz. The flip-flop is used for
synchronization between switching and Output clock.
9.4.6 UART (RS232)
UART2 (TXD2, RXD2, CTS2, and RTS2) is used for serial
communication with the CDR module. FREYA_TXD contains
serial data from Mozart to CDR. FREYA_RXD is received
data from CDR. FREYA_SUR and FREYA_CPR are used for
acknowledge and Flow-control.
9.4.7 Acknowledge
When a FREYA drive is connected, FREYA_SUR and
FREYA_CPR are used as acknowledge signals.
When Mozart transmits data to FREYA, FREYA
acknowledges each transmitted byte with a FREYA_CPR
low period.
When Mozart receives data from FREYA, Mozart
acknowledges each received Byte with FREYA_SUR low
period.
CDR Mozart 9.
CL 16532046_042.eps
Figure 9-4
Figure 9-5
TXD2
CPR
CL 16532046_029.eps
080501
Figure 9-6
GB 51
080501
CL 16532046_028.eps
080501