ES1371 Datasheet, PDF (6/37 Pages) List of Unclassifed Manufacturers – ENSONIQ AudioPCI 97 digital controller

ENSONIQ Proprietary Information
4.11. Internal Memory
There are two separate sections of memory in AudioPCI 97. One section is allocated as a cache for the
playback and record channels and also as a FIFO for the UART. The other section is allocated to the
Sample Rate Converter module and is used as a cache for sample rate conversion and also as control
register space for the playback and record channels in the sample rate converter.
The internal memory for the sound cache in AudioPCI 97 is organized as 4 blocks of 64 bytes each. Each
block is divided into 4 pages of 16 bytes each (4 longwords). Memory can be accessed as longwords only.
In order to access a specific page of memory the memory page register must first be setup for the specific
page to be accessed. The first three blocks of memory contain the 3 circular buffers for the 2 playback
channels and the record channel. The last block contains the frame information for the playback and record
channels and also includes the UART FIFO. The memory block and page organization is shown below :
Block
0 - DAC 1
1 - DAC2
2 - ADC
3 - Frame/UART
Page
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Higher
Address
Lower
DAC1 sample bytes 15 - 0 Lower half buffer
DAC1 sample bytes 31 - 16
DAC1 sample bytes 47 - 32 Upper half buffer
DAC1 sample bytes 63 - 48
DAC2 sample bytes 15 - 0 Lower half buffer
DAC2 sample bytes 31 - 16
DAC2 sample bytes 47 - 32 Upper half buffer
DAC2 sample bytes 63 - 48
ADC sample bytes 15 - 0 Lower half buffer
ADC sample bytes 31 - 16
ADC sample bytes 47 - 32 Upper half buffer
ADC sample bytes 63 - 48
DAC1, DAC2 frame information (see register descriptions)
ADC frame information (plus 2 open longwords)
UART fifo (only bits 8 - 0 of each longword are used)
UART fifo
ENSONIQ Proprietary Information
ENSONIQ AudioPCI 97 Specification Rev 1.1 Oct 1, 1997
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