saa7327 NXP Semiconductors, saa7327 Datasheet - Page 39

• Manufacturer Part Number: saa7327
• Description: Digital Servo Processor And Compact Disc Decoder With Integrated Dac For Video Cd Cd7 Ii
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7.15.3
To maintain compatibility with the SAA737x series,
decoder registers 0 to F are identical to the SAA7370.
However, to control the extra functionality of SAA7327, a
new set of registers called shadow registers have been
implemented.
These are accessed by using the LSB of decoder
register F. This bit is called SHADEN (shadow registers
enable) on SAA7327. When this bit is set to logic 1 (i.e.
decoder register F set to XXX1), any subsequent
addresses will be decoded by the shadow registers.
In fact, only four addresses are implemented as shadow
registers; 3, 7, A and C. Any other addresses sent while
SHADEN = 1 are invalid and have no effect.
7.15.4
Table 14 Registers 0 to F
2000 Jun 26
0
(fade and
attenuation)
1
(motor mode)
Digital servo processor and Compact Disc
decoder with integrated DAC for video CD (CD7 II)
REGISTER
D
S
UMMARY OF FUNCTIONS CONTROLLED BY DECODER REGISTERS
ECODER REGISTERS AND SHADOW REGISTERS
ADDRESS
0000
0001
DATA
1XXX
0XXX
X000
X001
X010
X011
X100
X101
X111
X110
0000
0010
0001
0100
0101
mute
attenuate
full-scale
step down
step up
motor off mode
motor stop mode 1
motor stop mode 2
motor start mode 1
motor start mode 2
motor jump mode
motor play mode
motor jump mode 1
anti-windup active
anti-windup off
39
When SHADEN is set to logic 0 (decoder register F set to
XXX0) all subsequent addresses are decoded by the main
decoder registers again.
Access to decoder register F is always enabled so that
SHADEN can be set or reset as required.
The SHADEN bit and subsequent shadow registers are
programmed identically to the main decoder registers, i.e.
they can be directly programmed when using SAA7327 in
4-wire mode or programmed via the servo interface when
using 3-wire or I
The main decoder registers are shown in Table 14. The
functions implemented using shadow registers are shown
in Table 16.
0
FUNCTION
TO
F
2
C-bus modes.
Product specification
SAA7327
INITIAL
reset
reset
reset
(1)