
AMBE-3000F™ Vocoder Chip Users Manual
Version 3.4, April, 2014
I/
O Management
(Subject to Change) Page 41
DVSI CONFIDENTIAL PROPRIETARY
“0 to Transition”“1”
“0 to Transition”“1”
TX_RQST
TX_RDY
9ms
8ms
20ms
“Packet_ _Zone”Uncertainty
5.625ms
5.625ms
20ms
Figure 23 TX_RDY with Skew Control On
5.2.2 Timing of channel receive packets in Codec Mode
In general, every time the AMBE-3000™ vocoder chip transmits a packet it should also receive a packet.
A
TX_RDY
9ms
8ms
20ms
Packet
BC
“Packet_ _Zone”Uncertainty
Figure 24 TX_RDY Timing
At time “A” the AMBE-3000™ Vocoder Chip sets TX_RDY high
When using the PPT packet interface
the reading of a packet from the PPT can begin.
When using the UART or MCBSP packet interface
the AMBE-3000™ Vocoder Chip will begin transmitting a channel packet.
During each 20 ms frame interval as indicated by the TX_RDY signal, the decoder should receive exactly one packet.
Between time “B” and “C” (the “Packet_Uncertainty_Zone”) the vocoder should not receive any channel packets.
The following figure illustrates the simplest way to send packets to the AMBE-3000™ Vocoder Chip
TX_RDY
Frame_Interval
n
Frame_Interval
n+1
Frame_Interval
n+2
Frame_Interval
n+3
20ms
“Packet_ _Zone”Uncertainty
Figure 25 TX_RDY Frame Interval
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