Cirrus Logic AN333 User Manual
Page 11
AN333
11
4 Operating System (OS) Firmware Module
Table 4-1. OS Firmware Manager
Index
Variable
Description
0x0000
KICKSTART
Bit 16: 0/1 Disable/enable malloc failure reporting.
Bit 13: 0/1 Disable/enable continual GPIO updating.
Only applicable if Bit 12 is set. If Bit 12 is disabled, audio pins are be available.
Bit 12: 0/1 Disable/enable GPIO updates.
Bit 9: 0/1 Disable/enable hardware watchdog timer reload.
Bit 8: 0/1 Disable/enable hardware watchdog timer.
When Bit 8 is set, the hardware watchdog timer is enabled. When the watchdog timer
is enabled, the timer with the initial set value starts decrementing, and when it reaches
zero, it stops decrementing and resets the hardware. Every 16 audio samples, there is
an option to reload the watchdog timer, controlled by bit 9. If bit 9 is set, a watchdog
timer reload does not take place. Otherwise, the counter is reloaded with the set value
every 16 audio samples.
Bit 0: Kick-start: Set to 1 to trigger kick-start
Default = 0x00000000
0x0001
IO_CONFIG
See
for the details of this index.
0x0002
OUTPUT_MODE_CONTROL
†
Bits 7:4 Dual Mono Mode (valid only if input mode is 0x0000)
0x0 = Stereo Mode => Center_out = None
Left_out = Left_in
Right_out = Right_in
0x1 = Left Mono => Center_out = Left_in
Left_out = None
Right_out = None
0x2 = Right Mono => Center_out = Right_in
Left_out = None
Right_out = None
0x3 = Mixed Mono => Center_out = (Lin+Rin)/2
Left_out = None
Right_out = None
For non-zero values (1,2 or 3) in bits 7:4 of the OUTPUT_MODE_CONTROL variable,
values in bits 3:0 are ignored.
Dual mono mode selection is available only if input mode is 0, that is for dual mono
streams.
Bits 3:0 Output Mode (number of speakers present in the system)
0x0 = 2/0 Lt, Rt Dolby Surround compatible
0x1 = 1/0 C
0x2 = 2/0 L/R
If the output mode is set to 0x02 and Dolby decoding is also set, then the output is Lt/
Rt or Lo/Ro depending on the setting of the AC3 Manager STEREO_MODE_
CONTROL. See AN333DA for more information.
0x3 = 3/0 L/C/R
0x4 = 2/1 L/R/S
0x5 = 3/1 L/C/R/S
0x6 = 2/2 L/R/Ls/Rs
0x7 = 3/2 L/C/R/Ls/Rs
0x8 = 3/3 L/C/R/Ls/Rs/Cs
0x9 = 3/4 L/C/R/Ls/Rs/Sbl/Sbr
0xA = 2/3 L/R/Ls/Rs/Cs
0xB = 2/4 L/R/Ls/Rs/Sbl/Sbr
Default = 0x00000007