319
ABOV Semiconductor Co., Ltd.
11.17 The Fine ADPCM Decoder
11.17.1 Overview
The fine ADPCM decoder has the decoder block to play voice promt and the interface block to read data of a serial
flash memory. The fine ADPCM has eighteen registers which are the decoder control register (DECCR), decoder FIFO
register (DFIFOR), decoder sampling frequency data register (DECDR), decoder bundle register (DBDLR), decoder
result output high/low register (DODRH/L), voice prompt control register (VPCR), serial flash dummy and data number
register (SFDDNO), serial flash command register (SFCMD), voice prompt address register 1/2/3 (VPADDR1/2/3),
voice prompt size register 1/2/3 (VPSIZE1/2/3) and voice prompt inform register 1/2 (VPINF1/2).
11.17.2 Function Description
The bundle size and sampling frequency should be set to decode voice prompt data. The sampling frequency is an
interval to play. It can be adjusted by the clock and sampling frequency data of the decoder. The clock source is
selected by clock selection logic which is controlled by the clock selection bits (DCLKS[1:0]). The clock source is fx/2,
fx/4, fx/8 and fx/16. The bundle size is a block unit to decode encoding data. The bundle size, “00H”, means 256-bytes
bundle structure of encoding data. The fine ADPCM decoder uses the auto-interface with a serial flash memory to
read the table data of voice prompt and the encoding data of the FADPCM format. The SPI2 or SPI3 can be selected
for interface by SPICSS bit (VPCR[4]). The table data of voice prompt consists of the block which has 3-bytes address,
3-bytes size and 2-bytes information.
To Next Page
Loading...
Need help?
General
