AMBE-2000™ Vocoder Chip Users Manual
Version 4.92, June, 08
DVSI Confidential Proprietary, Subject to Change
Page 15
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Pin Number
Pin Descriptive Name
Pin Direction
Notes
41
CODEC_TX_DATA
Output
PCM Data from AMBE-2020™ to D/A Converter
27
CODEC_RX_CLK
Input
A/D Serial clock. Should be connected to CODEC_TX_CLK
33
CODEC_TX_CLK
Input
D/A Serial clock Should be connected to CODEC_RX_CLK
51
CLOCK_MODE
Input
If high enables crystal oscillator option for clock source. If low then external oscillator
option is selected. See Section 3.5 for details.
8,11,12,23,
36,39,44,45,
46,47,48,
49,54,57,
64,76,87,90
V
DD
Power
Supply Voltage
1,9,10,25,
26,35,40,50,
52,53,56,
63,65,88,89
GND
Power
Ground
2,3,4,5,6,7,
13,14,15,16,
17,18,19,21,
22,43,55,58,
59,60,61,62,
66,78,91,92,
93,94,95,96,
97,98,99,
100
No Connection
These pins must remain unconnected
NOTE 1: The AMBE-2020™ expects an encoder packet to be read approximately every 20 msec. Following the initial reset,
wait for EPR to go low and read the initial packet (t
0
). 20 msec later, the next packet (t
1
) should be ready. For packet t
1
and all
following packets use the procedure below:
1)
Wait for slightly less than 20 msec.
2)
Assert CHAN_TX_STB and read word on CHAN_TX_DATA.
3)
If transmitted word not 0x13EC, discard it and repeat step 2.
4)
If transmitted word 0x13EC, read 23 more words (rest of packet).
The EPR signal should not be used as an interrupt. The EPR is only valid for the first high to low transition.
A new packet should be ready every 20 msec after the initial EPR high to low transition. A packet read should take place
every 20 msec. If there is a delay in the read (i.e. a packet is missed), it is recommended that the device be reset.
NOTE 2: To prevent possible damage to the chip be sure that your circuit meets the following three requirements.
1)
No signals should be applied to the device (this includes clocks) before the power is applied.
2)
The clock and reset must be applied to the device during power up. If the clock and reset are not applied during
power up, high currents may flow damaging the device.
3)
All of the configuration I/O pins of the device should be pulled up or pulled down through individual 10 K ohm
resistors to limit current flow through the I/O sections. See Table below for the affected pins.
Descriptive Name
Pin Number
Descriptive Name
Pin Number
CHAN_SEL1
77
VAD_EN
86
CHAN_SEL0
75
ENCODER_EN
24
CODEC_SEL1
85
SLEEP_EN
83
CODEC_SEL0
84
SLIP_EN
82
RATE_SEL4
74
SPFT_EN
79
RATE_SEL3
73
BAUD_SEL0
80
RATE_SEL2
72
BAUD_SEL1
81
RATE_SEL1
71
RATE_SEL0
70
