MAS 35x9F
DATA SHEET
Table 3–9: D0 control memory cells, continued
Memory
Address
(hex)
Function
Name
D0:34d
Operation Mode Selection (reset = 0
)
G.729
UserControl
hex
The register is used to switch between basic G.729 operation modes.
bit[19:7]
bit[6]
Reserved, set to 0
Page headers
0
1
enable
disable
If the page headers bit is 0, a header frame is transfered before each page of
50 data frames. If the header bit is 1, all the frames are G.729 data frames.
Please (see Section 3.3.8. on page 44).
bit[5:4]
Decoding speed
00
01
10
11
8 kHz (normal)
6 kHz (slow)
12 kHz (fast)
not allowed
The recording (encoding) is always done with a sampling rate of 8 kHz. During
decoding this control can be used to speed up or slow down the playback.
bit[3]
bit[2]
Reserved, set to 0
Pause encoder/decoder
0
1
normal operation
pause
If the pause bit is set, the processing continues until the current page is fin-
ished and then en-/decoding is paused. The pause mode lasts until the pause
bit is cleared again or the mode is set to 0.
bit[1:0]
Mode
00
idle
01
10
11
decode
not allowed
encode
To switch to encoder operation mode, UserControl has to be set to 3 . Then
hex
50 frames are encoded and sent via the PIO interface. This is repeated until
the UserControl register is changed. If the transmission of headers is enabled,
each page of 50 frames is preceeded by a header frame as shown in Fig. 3–4
on page 44.
To switch to decoder operation mode, UserControl has to be set to 1 . For
hex
decoding with slow speed, UserControl must be 11 , for decoding with fast
hex
speed it must be 21 . Then the decoder is requesting several frames via the
hex
PIO interface to fill its internal buffer. If enough data is available, 50 frames are
decoded. This is repeated until the UserControl register is changed. If the
transmission of headers is enabled, a header frame has to be sent before
each page of 50 frames (see Fig. 3–4 on page 44).
To switch off the encoder or decoder, UserControl has to be set to 0 . Then
hex
the encoding/decoding and sending/receiving of frames continues until the
end of the current page and the operation mode is set to stop.
36
June 30, 2004; 6251-505-1DS
Micronas
MICRONAS [ MICRONAS ]
