Specifications

ESS Technology, Inc. SAM0025A-062397 85
ES1879 DATA SHEET
AUDIO MICROCONTROLLER COMMAND SUMMARY
PRELIMINARY
64h 2 writes
Start
ESPCM
®
4.3-bit (low compression) format DMA transfer to DAC. Data is transfer count-1, least
byte first.
65h 2 writes Same as command 64h, except with Reference Byte flag.
66h 2 writes
Start
ESPCM
®
3.4-bit (medium compression) format DMA transfer to DAC. Data is transfer count-1,
least byte first.
67h 2 writes Same as command 66h, except with Reference Byte flag.
6Ah 2 writes
Start
ESPCM
®
2.5-bit (high compression) format DMA transfer to DAC. Data is transfer count-1, least
byte first.
6Bh 2 writes Same as command 6Ah, except with Reference Byte flag.
6Eh 2 writes
Start
ESPCM
®
4.3-bit (low compression) format ADC, compression, and DMA transfer. Data is trans-
fer count-1, least byte first.
6Fh 2 writes Same as command 6Eh, except with Reference Byte flag.
74h 2 writes Start ADPCM 4-bit format DMA transfer to DAC. Data is transfer count-1, least byte first.
75h 2 writes Same as command 74h, except with Reference Byte flag.
76h 2 writes Start ADPCM 2.6-bit format DMA transfer to DAC. Data is transfer count-1, least byte first.
77h 2 writes Same as command 76h, except with Reference Byte flag.
7Ah 2 writes Start ADPCM 2-bit format DMA transfer to DAC. Data is transfer count-1, least byte first.
7Bh 2 writes Same as command 7Ah, except with Reference Byte flag.
80h 2 writes Generate silence period. Data is number of samples-1.
90h Start Auto-Initialize, DMA 8-bit transfer to DAC. Transfer count must be previously set by command
48h.
91h Start DMA 8-bit transfer to DAC. Transfer count must be previously set by command 48h.
98h Start High-Speed mode, Auto-Initialize, DMA 8-bit transfer from ADC. Transfer count must be previ-
ously set by command 48h. There is no AGC. Input volume is controlled with command DDh. Maxi-
mum sample rate is 44 kHz.
99h Start High-Speed mode, DMA 8-bit transfer from ADC. Transfer count must be previously set by
command 48h. There is no AGC. Input volume is controlled with command DDh. Maximum sample
rate is 44 kHz.
Axh, Bxh,
Cxh
(where x = 00h to 0Fh) ES1879 Extension commands. Many of the Extension commands are used
to access the ES1879’s controller registers. For information on these registers, see the register
descriptions.
C0h Enable reads of ES1879 registers used for Extended Mode: Axh, Bxh.
C1h Resume after suspend.
C6h Enable ES1879 Extension commands Axh, Bxh. Must be issued after every reset.
C7h Disable ES1879 Extension commands Axh, Bxh.
D0h Pause DMA. Internal FIFO operations will continue until the FIFO is empty (DAC transfer) or full
(ADC transfer). It is not necessary to use this command to stop DMA if the transfer is completed nor-
mally and the end-of-DMA interrupt is generated.
D1h Enable voice DAC input to mixer.
D3h Disable voice DAC input to mixer.
D4h Continue DMA after command D0h.
D8h 1 read Return voice DAC enable status:
0 = disabled
FFh = enabled
Table 28 Command Summary (Continued)
Command
Data Byte(s)
Write/Read
Function