Specifications

34 SAM0025A-062397 ESS Technology, Inc.
ES1879 DATA SHEET
CONFIGURATION
PRELIMINARY
GPI Map (27h, R)
One bit for each GPI[6:0]. This register is reset to zero by
hardware reset but not by PnP reset.
Bit Definitions:
MPU-401 and Hardware Volume IRQ (28h, R)
Bit Definitions:
Miscellaneous Digital Control (29h, R/W)
This register is reset to 21h by hardware reset but not by
PnP reset. The hardware reset default format is I
2
S.
Bit Definitions:
Special Volume (2Ah, R)
This register is reset to 0Eh by hardware reset but not by
PnP reset.
Bit Definitions:
x GPI6 GPI5 GPI4 GPI3 GPI2 GPI1 GPI0
76543210
Bits Name Description
7 — Don’t care.
6:0 GPI[6:0] 1 = GPI pin controls corresponding GPO pin of
the ES978.
0 = GPO pins of the ES978 controlled by port
Configuration_Device_Base+3h, not by the
GPI pins of the ES1879.
Hardware volume IRQ number MPU-401 IRQ number
76543 210
Bits Name Description
7:4 Hardware
volume
IRQ num-
ber
Hardware volume IRQ number. This number
must be shared with audio 1 or audio 2.
6:0 MPU-401
IRQ num-
ber
MPU-401 IRQ number. Alias address with
register 70h of MPU-401 LDN 3.
DRQ latch
enable
I
2
S port
enable
I
2
S port
function
MIDI loopback
test enable
x
Digital
joystick
enable
ES978
joystick
enable
7654321 0
Bits Name Description
7 DRQ
latch
enable
1 = DRQ latch feature enabled.
0 = DRQ latch feature disabled (default).
6
I
2
S port
enable
1 = I
2
S port enabled.
0 = I
2
S port disabled (hardware reset default).
5:4
I
2
S port
function
Selects the function for the I
2
S port.
bit 5
bit 4 function
0 0 ES689/ES69x. IIData is data.
IISCLK is bit clock. IILR should
connect low or float.
0 1 Reserved.
1 0 I
2
S port is x384 oversampling
(hardware reset default).
1 1 Reserved.
3 MIDI
loopback
test
enable
1 = Enable ES978 MIDI loopback test.
0 = Disable ES978 MIDI loopback test.
2 – Don’t care.
1Digital
joystick
enable
1 = Digital joystick.
0 = Analog joystick (default).
0 ES978
joystick
enable
1 = Use ES978 joystick when docked (default).
0 = Use ES1879 joystick when docked.
Volume mixed into ES978 record Volume mixed into ES978 playback
76543 210
Bits Name Description
7:4 Volume
mixed
into
ES978
record
Volume of host audio mixed into ES978 record
mixer (default = 0).
3:0 Volume
mixed
into
ES978
playback
Volume of host audio mixed into ES978 play-
back mixer (default = 0Eh).