AMD LX 900@1.5W Computer Hardware User Manual


 
258 AMD Geode™ LX Processors Data Book
Graphics Processor Register Definitions
33234H
6.4.1.5 GLD Power Management MSR (GLD_MSR_PM)
This MSR contains the power management controls for the GP. Since there is only one clock domain within the GP, most
bits in this register are unused. This register allows the GP to be switched off by disabling the clocks to this block. If hard-
ware clock gating is enabled, the GP will turn off its clocks whenever there is no BLT busy or pending and no GLIU transac-
tions destined to the GP. A register or MSR write causes the GP to wake up temporarily to service the request, then return
to power down. A write to the GP_BLIT_MODE or GP_VECTOR_MODE registers (GP Memory Offset 40h and 3Ch
respectively) causes the GP to wake up for the duration of the requested operation. If software clock gating is enabled, a
write to the PRQ bit causes the GP to stop its clocks the next time that it is idle. It automatically wakes itself up when it is
busy again, clearing the PRQ bit.
6.4.1.6 GLD Diagnostic MSR (GLD_MSR_DIAG)
This register is reserved for internal use by AMD and should not be written to.
GLD_MSR_ERROR Bit Descriptions
Bit Name Description
63:18 RSVD Reserved. Read returns 0.
17 AE Address Error. 1 indicates address violation. Write = 1 clears bit, write = 0 has no effect.
16 TE Type Error. 1 indicates type error. Write = 1 clears bit, write = 0 has no effect.
15:2 RSVD Reserved. Read returns 0.
1AM Address Mask. Ignore address violations when set.
0TM Type Mask. Ignore type violations when set.
MSR Address A0002004h
Typ e R /W
Reset Value 00000000_00000000h
GLD_MSR_PM Register Map
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
RSVD
PRQ
313029282726252423222120191817161514131211109876543210
RSVD PM
GLD_MSR_PM Bit Descriptions
Bit Name Description
63:33 RSVD Reserved. Read returns 0.
32 PRQ Software Power Request. If software clock gating is enabled, disable the clocks the next
time the device is not busy. This bit is cleared when the device wakes up.
31:2 RSVD Reserved. Read returns 0.
1:0 PM Power Mode.
00: Disable clock gating. Clocks are always on.
01: Enable active hardware clock gating.
10: Enable software clock gating.
11: Enable hardware and software clock gating.
MSR Address A0002005h
Typ e R /W
Reset Value 00000000_00000000h