LSI Logic Confidential
16-10
Clock Control and Power Management
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
Power Management Register
Cbus Address: 0xC20000
Note:
The Power Management Register at control bus address
0xC20000 is used to selectively disable DMN-8600
modules as well as power down all internally clocked logic.
After reset, all PLLs and modules are enabled so that all
subblocks can be reset. After the power up sequence is
completed, individual units can be disabled by software to
save power. All unused bits should be written with 0 and
are read as 0.
Main_PLL_Off
31
Power down main PLL, crystal oscillator and internally
clocked logic when set. Can only be cleared by Reset.
Since Main PLL may not be running during reset, the
power down signal to the Main PLL is overridden by
reset. Programming note: An external host, rather than
the internal SPARCs, should set this bit. After the host
sets this bit, it should not perform a host access for at
least 10 microseconds.
Video_PLL_Off
30
Power down video out PLL, and internally clocked video
output processing when set. When cleared, video output
timing will not be stable for 1 ms.
Ain_PLL_Off
29
Power down Audio In PLL when set. When cleared, audio
input PLL timing will not be stable for 1 ms.
Aout_PLL_Off
28
Power down Audio Out PLL when set. When cleared,
audio output PLL timing will not be stable for 1 ms.
31
30
29
28
27
26
16
Main_PLL_Off Video_PLL_Off Ain_PLL_OFF Aout_PLL_Off Xtal_OSC_Off
15
13
12
0
Clock_Buf_Disable