Specifications

AMBE-3000™ Vocoder Chip Users Manual
Version 2.8, August, 2011
I/
O Management
5.2 SPI Interface
The serial peripheral interface (SPI) is a high-speed, synchronous serial I/O port that can be used as the speech interface to the
codec. This interface allows a serial bit stream to be transferred between the AMBE-3000™ Vocoder Chip and an audio
codec. The interface includes four-pins. The SPI interface is designed for speech data only and may be used only in codec
mode.
Pin
TQFP BGA
Pin Name Direction Description
27 K2 SPI_CLK Input A/D Serial clock.
28 K4 SPI_STE Input
The framing signal generated from
SPI_GENSTE.
31 M1 SPI_RX_DATA Input
PCM Data from A/D Converter to AMBE-
3000™ Vocoder Chip
32 N1 SPI_TX_DATA Output
PCM Data from AMBE-3000™ Vocoder Chip
to D/A Converter
Table 17 SPI Interface Pins
Figure 21 SPI Timing
The SPI_STE signal is asserted low at least 136 ns before the valid SPI_CLK edge and remains low for at least 136 ns after the
receiving edge of the last data bit.
MIN MAX
SPI_CLK Cycle time (t
SPI
) 272 ns 7.8 µs
SPI_CLK low Pulse duration (t
wL
) 126 ns 3.9 µs
SPI_CLK high Pulse duration (t
wH
) 126 ns 3.9 µs
Table 18 SPI Timing
(Subject to Change) Page 40
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