SAA7115HLBE NXP Semiconductors, SAA7115HLBE Datasheet - Page 148

Video ICs ADV DGTL VIDEO DECODR

SAA7115HLBE

Manufacturer Part Number
SAA7115HLBE
Description
Video ICs ADV DGTL VIDEO DECODR
Manufacturer
NXP Semiconductors
Datasheet

Specifications of SAA7115HLBE

Operating Supply Voltage
3.3 V
Maximum Operating Temperature
+ 70 C
Package / Case
SOT-407
Minimum Operating Temperature
0 C
Mounting Style
SMD/SMT
Number Of Channels
2
Resolution
8 bit
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
SAA7115HL/V1,557 SAF7115HLBE
PNX1300/01/02/11 Data Book
9.4.2
TM-1000 clock compatibility mode is provided so that
TM-1000 audio software runs without changes. It should
NOT be used for new software development, due to a 3x
higher jitter. TM-1000 mode is automatically entered
whenever FREQUENCY[31] = 0. In TM-1000 mode,
AO_OSCLK frequency is set as follows:
9.5
The output of the DDS is always sent to the AO_OSCLK
output pin. This output is typically used as the 256f
384f
ers, such as the Philips SAA7322, or codecs such as the
AD1847, CS4218 or UD1340.
AO_WS and AO_SCK are sent to each external D/A con-
verter in the master mode.
AO_WS, the word strobe, determines the sample rate:
each active channel receives one sample for each
AO_WS period.
AO_SCK is the data bit clock. The number of AO_SCK
clocks in an AO_WS period is the number of data bits in
a serial frame required by the attached D/A converter.
AO_WS is a divider of the bit clock and is set using WS-
DIV to control the serial frame length. The number of bits
per frame is equal to WSDIV+1. There are some mini-
mum length requirements for a serial frame, refer to
Section
AO_SCK and AO_WS can be configured as input or out-
put, as determined by the SER_MASTER control field. If
set as output, AO_SCK can be set to a divider of the DDS
output frequency.
Whether set as input or output, the AO_SCK pin signal is
always used as the bit clock for parallel-serial conver-
sion. The AO_WS pin always acts as the trigger to start
the generation of a serial frame. AO_WS can similarly be
programmed using WSDIV to control the serial frame
length. The number of bits per frame is equal to WS-
DIV+1.
The preferred use of the clock system options is to use
AO_OSCLK as D/A master clock, and let the D/A con-
9-4
Figure 9-2. Definition of serial frame bit positions (POLARITY = 1, CLOCKEDGE = 0)
AO_WS
AO_SDx
AO_SCK
frame
s
f
system clock source for oversampling D/A convert-
AOSCK
n-1
FREQUENCY
CLOCK SYSTEM OPERATION
9.6.1.
30
TM-1000 Compatibility Mode
31
=
0
--------------------------------- -
SCKDIV
f
1
AOOSCLK
2
3
PRELIMINARY SPECIFICATION
+
=
4
1
5
f
----------------------------- -
3 f
OSCLK
6
DSPCPU
7
SCKDIV
8
2
9
32
10
11
[ ,
12
0 255
13
]
14
15
s
or
16
frame
17
18
Table 9-4. AO MMIO Clock & Interface Control
verter be a timing slave of the serial interface
(SER_MASTER=1). This is important in view of compat-
ibility with future Trimedia devices, which may only sup-
port the AO unit as serial interface master.
Some D/A converters however, like the AD1847, provide
better SNR properties if they are configured as serial
master, with the AO unit as slave (SER_MASTER=0). As
illustrated by
converter that constructs the serial frame is oblivious to
which component is timing master.
9.6
The AO unit can generate data in a wide variety of serial
data framing conventions.
tion of a serial frame. If POLARITY=1, a frame starts with
a positive edge of the AO_WS signal. If POLARITY=0, a
serial frame starts with a negative edge on AO_WS. If
CLOCK_EDGE=0, the parallel to serial converter sam-
ples AO_WS on a positive clock edge transition, and out-
puts the first bit (bit 0) of a serial frame on the next falling
edge of AO_SCK.
If CLOCK_EDGE=1, the parallel to serial converter sam-
ples AO_WS on the negative edge of AO_SCK, while au-
dio data is output on the positive edge, i.e. the AO_SCK
polarity would be reversed with respect to
n
SER_MASTER
FREQUENCY
SCKDIV
WSDIV
19
Field Name
20
21
SERIAL DATA FRAMING
22
23
24
Figure
25
0 ⇒ (RESET default), the D/A subsystem
1 ⇒ PNX1300 is the timing master over
The SER_MASTER bit should only be
changed while the AO unit is disabled, i.e.
TRANS_ENABLE = 0.
Sets the clock frequency emitted by the
AO_OSCLK output. RESET default 0.
Sets the divider used to derive AO_SCK
from AO_OSCLK. Set to 0..255, for divi-
sion by 1..256. RESET default 0.
Sets the divider used to derive AO_WS
from AO_SCK. Set to 0..511 for a serial
frame length of 1..512. RESET default 0.
26
9-1, the internal parallel to serial
27
is the timing master over the AO
serial interface. AO_SCK and
AO_WS act as inputs.
the serial interface. AO_SCK and
AO_WS act as outputs. This mode is
required for 4,6 or 8 channel opera-
tion.
28
29
Philips Semiconductors
Figure 9-2
30
Description
31
0
1
illustrates the no-
2
frame
Figure
3
n+1
4
5
9-2.
6
7

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