Advanced I/O Controller with Motherboard GLUE Logic
Datasheet
RMB_SCK
MCH
V_5P0_STBY
1k
SCK_BJT_GATE
SMSC I/O
Figure 7.13 - SCK_BJT_GATE Circuit
See Table 13.4 for SCK_BJT_GATE timing.
7.39 Backfeed Cut and Latched Backfeed Cut Circuitry
Table 7.42 – nBACKFEED_CUT and LATCHED_BF_CUT Pins
Name
Buffer
Power
Well
Description
nBACKFEED_CUT
LATCHED_BF_CUT
OD8
OP14
VTR
VTR
Open-Drain Output used for
STR Circuitry
Latched Backfeed Cut Output
for STR Circuitry
Note:
The nBACKFEED_CUT requires an external pull-up to V_5P0_STBY.
nBACKFEED_CUT is a signal required by the S3 power state circuitry and is powered by the VTR supply.
It is a function PWRGD_PS and nSLP_S3 according to the table below. nBACKFEED_CUT is used to
switch between the main voltage regulator and the suspend voltage regulator for various sub-systems
when the system is transitioning into the S3 power state.
Table 7.43 – nBACKFEED_CUT Truth Table
INPUTS
OUTPUT
nBACKFEED_CUT
PWRGD_PS
NSLP_S3
0
0
1
1
0
1
0
1
Hi-Z
Hi-Z
Hi-Z
0
SMSC LPC47M182
147
Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)
DATASHEET
SMSC [ SMSC CORPORATION ]
