Specifications

70 SAM0025A-062397 ESS Technology, Inc.
ES1879 DATA SHEET
REGISTERS
PRELIMINARY
Spatializer Audio Processor Registers
This section describes registers related to the Spatializer
3-D audio processor.
Spatializer Enable and Mode Control (50h, R/W)
Reset to zero by hardware reset.
Bit Definitions:
Spatializer Level/Limit (52h, R/W)
Reset to zero by hardware reset.
Bit Definitions:
Spatializer Auto-Limit Scale Factor 1 (54h, R/W)
This register, along with mixer register 56h, is used to set
scale factors used by the automatic limit mechanism.
Program this register to 8Fh (143 decimal) as shown.
Recommended values are subject to change in the future.
Reset to zero by hardware reset.
Spatializer Auto-Limit Scale Factor 2 (56h, R/W)
This register, along with mixer register 54h, is used to set
scale factors used by the automatic limit mechanism.
Program this register to 95h (149 decimal) as shown.
Recommended values are subject to change in the future.
Reset to zero by hardware reset.
Spatializer Auto-Limit Mode Rate (58h, R/W)
The recommended value for this register is 94h:
Max_Decrease_Rate = 276 Hz
Max_Increase_Rate = 2480 Hz
Reset to zero by hardware reset.
Bit Definitions:
Spatializer Auto-Limit Threshold and Offset(5Ah,R/W)
Reset to zero by hardware reset.
Bit Definitions:
0 0 0 0 Spatializer enable Reset Mono mode Auto-limit
7654 3 2 1 0
Bits Name Description
7:4 0 Reserved. Always write 0.
3 Spatial-
izer
enable
1 = Enable Spatializer effect.
0 = Disable Spatializer effect (effect unit
bypassed).
2 Reset 1 = Release from reset.
0 = Reset Spatializer.
1 Mono
mode
1 = Mono-in, stereo-out mode.
0 = Stereo-in, stereo-out mode.
0 Auto-limit 1 = Enable automatic effect limiter.
0 = Disable automatic effect limiter.
0 0 Spatializer level/limit
7654 3 2 1 0
Bits Name Description
7:6 0 Reserved. Always write 0.
5:0 Spatializer
level/
limit
0 is minimum effect; 3Fh is maximum effect. If
the auto-limit function is enabled (mixer regis-
ter 50h bit 0), then this register specifies the
maximum effect level (actual effect determined
by automatic level setting mechanism). If the
auto-limit function is disabled, then this register
sets the current effect level.
1000 1 1 1 1
7654 3 2 1 0
10010101
76543210
Auto-limit increase rate Auto-limit decrease rate
76543210
Bits Name Description
7:4 Auto-
limit
increase
rate
Specifies the rate at which gain can be
increased, relative to the decrease rate:
Max_Increase_Rate =
Max_Decrease_Rate/(N+1); N is bits 7:4 of this
register.
3:0 Auto-
limit
decrease
rate
Specifies the rate at which gain can be
decreased:
Max_Decrease_Rate = 1378 Hz / (N+1)
N is bits 3:0 of this register.
Auto-limit low-level effect boost
Threshold
enable
Auto-limit energy threshold
7654 3 2 1 0
Bits Name Description
7:4 Auto-limit
low-level
effect boost
Increases Spatialization effect for low-level
signals.
3 Threshold
enable
1 = Enable auto-limit energy threshold
requirement.
0 = Disable auto-limit energy threshold
requirement.
2:0 Auto-limit
energy
threshold
1 = Enable minimum energy level setting of
input signal to make auto-limit decisions.
0 = Disable minimum energy level setting of
input signal.