BU8710AKS Datasheet, PDF (18/32 Pages) Rohm – 4-channel ADPCM transcoder for digital cordless telephone base stations

Communication ICs
BU8710AKS
S Command No.: 7 (VDET FLAG)
For channels on which encoder silence detection is en-
abled by register VDFxxx (command no. : 6), a flag can
be read out which indicates a silent status (HIGH). This
flag can only be read and cannot be written.
VDFE1A ^{G G G G} Silence detection flag for Channel 1-A en-
coder
VDFE1B ^{G G G G} Silence detection flag for Channel 1-B en-
coder
VDFE2A ^{G G G G} Silence detection flag for Channel 2-A en-
coder
VDFE2B ^{G G G G} Silence detection flag for Channel 2-B en-
coder
S Command No.: 8 (VDET L-LEVEL)
S Command No.: 9 (VDET U-LEVEL)
When encoder silence detection is being carried out,
these set the reference level on which judgments are
based. This set value is supplied as a 13-bit linear abso-
lute value.
VDLV12 X 00 ^{G G G G} Sets reference level on which encod-
er silence detection judgments are
based.
S Command No.: A (VDET TIME)
When encoder silence detection is carried out, this sets
the time interval for judgment. The set value issupplied
in 6 bits.
VDTIM5 X 0 ^{G G G G} Sets the time for judgment of encoder
silence. The time is calculated using
the equation below.
[Judgment time] = VDTIM 8ms
Ex.: If VDTIM = 110000 (binary), the judgment time
will be 48 8ms = 384ms
S Command No.: B (OUT LEVEL)
By writing the desired value to the corresponding internal
register, the decoder output level for each individual
channel can be attenuated to the desired level. In data
through mode or data loop back mode, the output level
cannot be controlled.
OLV1A1, OLV1A0 ^{G G G G} Output level control of Channel
1-A decoder
OLV1B1, OLV1B0 ^{G G G G} Output level control of Channel
1-B decoder
OLV2A1, OLV2A0 ^{G G G G} Output level control of Channel
2-A decoder
OLV2B1, OLV2B0 ^{G G G G} Output level control of Channel
2-B decoder
Two bits of control data are assigned to each channel,en-
abling adjustment in a total of four stages. The relation-
ship between the set value and the output level is shown
116
in the table below. The output levels noted here are
recorded using the value prior to attenuation (0dB) as a
reference.
S Command No.: C (THRU MODE)
Writing “H” to the corresponding internal register sets the
64kbps data through mode for the individual encoders
and decoders of the various channels.
THRE1A ^{G G G G} 64 kbps data through mode for Channel
1-A encoder
THRE1B ^{G G G G} 64 kbps data through mode for Channel
1-B encoder
THRE2A ^{G G G G} 64 kbps data through mode for Channel
2-A encoder
THRE2B ^{G G G G} 64 kbps data through mode for Channel
2-B encoder
THRD1A ^{G G G G} 64 kbps data through mode for Channel
1-A decoder
THRD1B ^{G G G G} 64 kbps data through mode for Channel
1-B decoder
THRD2A ^{G G G G} 64 kbps data through mode for Channel
2-A decoder
THRD2B ^{G G G G} 64 kbps data through mode for Channel
2-B decoder