LPC47M182 SMSC Corporation, LPC47M182 Datasheet - Page 137

• Manufacturer Part Number: LPC47M182
• Description: ADVANCED I/O CONTROLLER WITH MOTHERBOARD GLUE LOGIC
• Manufacturer: SMSC Corporation

Advanced I/O Controller with Motherboard GLUE Logic
Datasheet
Note:
SMSC LPC47M182
NSLP_S5
The LED is ON in the Hi-Z state. The LED is blinking at 0.67 Hz in the 0.67 Hz state.
The 32.768 kHz clock input is used to control the blink rate and duty cycle of the LEDs. The blink rate is
0.67Hz, and the duty cycle is 39.6%. This corresponds to a LED low output of exactly 0.90625 seconds
(depending on the accuracy of the 32.768 kHz clock).
YLW_LED and GRN_LED require external pull-ups to power the LEDs. A resistor value of 220 ohms  t o
VTR is recommended. These are open drain active high outputs. When the LEDs are off, the open drain
output is sinking the current from VTR through the 220 ohm resistor to ground. When the LEDs are on,
they are powered through the 220 ohm resistor.
The following figure shows the recommended external LED circuit.
0
0
0
0
1
1
1
1
SMSC I/O
GRN_YLW BIT
Figure 7.7 – Example Yellow and Green LED Circuit
INPUTS
0
0
1
1
0
0
1
1
Table 7.23 - LED Truth Table
DATASHEET
GRN_LED
YLW_LED
SDY_BLK BIT
137
0
1
0
1
0
1
0
1
220 ohms
Green
Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)
GRN_LED
0.67 Hz
Hi-Z
VTR
0
0
0
0
0
0
OUTPUTS
220 ohms
Yellow
YLW_LED
0.67 Hz
Hi-Z
0
0
0
0
0
0