SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 43

• Manufacturer Part Number: SCH3112I-NE
• Description: LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
• Manufacturer: SMSC [SMSC Corporation]

LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
Datasheet
SMSC SCH311X
4.5
4.6
■
Vbat is a battery generated power supply that is needed to support the power recovery logic. The
power recovery logic is used to restore power to the system in the event of a power failure. Power
may be returned to the system by a keyboard power button, the main power button, or by the power
recovery logic following an unexpected power failure.
The Vbat supply is 3.0 Volts (nominal). See
The following Runtime Registers are powered by Vbat:
■
■
■
■
■
■
■
■
■
■
■
■
Note: All Vbat powered pins and registers are powered by VTR when VTR power is on and are
The SCH311X utilizes a 32.768 KHz trickle input to supply a clock signal for the WDT, LED blink,
Power Recovery Logic, and wake on specific key function.
Indication of 32KHZ Clock
There is a bit to indicate whether or not the 32KHz clock input is connected to the SCH311X. This bit
is located at bit 0 of the CLOCKI32 register at 0xF0 in Logical Device A. This register is powered by
VTR and reset on a VTR POR.
Bit[0] (CLK32_PRSN) is defined as follows:
Vbat Support
32.768 KHz Trickle Clock Input
GPIOs (GP21-GP22, GP27, GP32, GP33, GP50-GP57, GP60, GP61) – all input-only except GP60,
GP61. See below.
Other Pins
GP60/LED1 (output, buffer powered by VTR)
GP61/LED2 (output, buffer powered by VTR)
nRSMRST
PWRGD_PS
PB_IN#
PB_OUT#
PS_ON#
nFPRST
SLP_SX#
PWRGD_OUT
Bank 2 of the Runtime Register block used for the 32kbyte Security Key register
PME_EN7 at offset 10h
PWR_REC Register at offset 49h
PS_ON Register at offset 4Ah
PS_ON Previous State Register at offset 53h
DBLCLICK register at offset 5Bh
Keyboard Scan Code – Make Byte 1 at offset 5Fh
Keyboard Scan Code – Make Byte 2 at offset 60h
Keyboard Scan Code – Break Byte 1 at offset 61h
Keyboard Scan Code – Break Byte 2 at offset 62h
Keyboard Scan Code – Break Byte 3 at offset 63h
Keyboard PWRBTN/SPEKEY at offset 64h
battery backed-up when VTR is removed.
DATASHEET
27
Chapter 28, "Operational Description," on page
Rev 0.2 (09-28-04)
339.