MiTAC 8355 VT8235 South Bridge-8, Internal Keyboard Controller, AC97 Audio /Modem Interface

8355 N/B MAINTENANCE

5.3 VT8235 South Bridge-8

Internal Keyboard Controller

Signal Name	Pin #	I/O	PU	Signal Description
MSCK /IRQ1	W2	IO/I	PU	MultiFunction Pin (Internal mouse controller enabled by
				Rx51[1]) Rx51[1]=1 Mouse Clock. From internal mouse
				controller. Rx51[1]=0 Interrupt Request 1 .Interrupt
				input 1.
MSDT /IRQ12	W1	IO/I	PU	MultiFunction Pin (Internal mouse controller enabled by
				Rx51[1]) Rx51[1]=1 Mouse Data. From internal mouse
				controller. Rx51[1]=0 Interrupt Request 12. Interrupt
				input 12.
KBCK /KA20G	V3	IO /I	PU	MultiFunction Pin (Internal keyboard controller enabled
				by Rx51[0]) Rx51[0]=1 Keyboard Clock. From internal
				keyboard controller Rx51[0]=0 Gate A20.Input from
				external keyboard controller.
KBDT /KBRC	V2	IO/I	PU	MultiFunction Pin (Internal keyboard controller enabled
				by
				Rx51[0])
				Rx51[0]=1 Keyboard Data. From internal keyboard
				controller.
				Rx51[0]=0 Keyboard Reset. From external keyboard
				controller (KBC)for CPURST# generation
KBCS#/ROMCS#/srap	AF12	O/O		Keyboard Chip Select (Rx51[0]=0).To external
				keyboard controller chip. Strap high o enable LPC ROM:

Note: KBCK,KBDT,MSCK,and MSDT are powered by the VSUS33 suspend voltage plane.

AC97 Audio /Modem Interface

Signal Name	Pin #	I/O	Signal Description
ACRST#	R3	O	AC97 Reset.
ACBTCK	T3	I	AC97 Bit Clock.
ACSYNC	T1	O	AC97 Sync.
ACSDO	U1	O	AC97 Serial Data Out.
ACSDIN0 (VSUS33)	T2	I	AC97 Serial Data In 0.
ACSDIN1 (VSUS33)	U3	I	AC97 Serial Data In 1.
ACSDIN2 /GPIO20 /PCS0#	U2	I	AC97 Serial Data In2.RxE4[6]=0,E5[1]=0,PMIO
			Rx4C[20]=1
ACSDIN3/GPIO21	V1	I	AC97 Serial Data In 3.RxE4[6]=0,E5[2]=0,PMIO
/PCS1#/SLPBTN#			Rx4C[21]=1

The supply voltage for ACSDIN0-1 is VSUS33 so these inputs can support wake-up on modem ring

Power and Ground

Signal Name	Pin #	I/O	Signal Description
VCC33	(see pin list)v	P	I/O Power.3.3V ±5%
VCC	(see pin list)	P	Core Power.2.5V ±5%.This supply is turned on only when he
			mechanical switch on the power supply is turned on and he
			PWRON signal is conditioned high .
			Note: The VT8235L core voltage is 2.5V so board designs that
			are intended t all w use of either VT8235 or VT8235L should
			take this difference into account and allow the core voltage to
			be selected as either 2.5V (for the VT8235)or 3.3V (for the
			VT8235L).
GND	(see pin list)	P	Ground. Connect o primary motherboard ground plane.
VSUS33	AA4,AB4,	P	Suspend Power.3.3V ±5%.Always available unless the
	AC4,AC5		mechanical switch of the power supply is turned off. If the
			“soft-off”state is not implemented, then this pin can be
			Connected to VCC33.Signals powered by or referenced o this
			plane are:PWRGD, RSMRST#,PWRBTN#,SMBCK1/2,
			SMBDT1/2,GPO0,SUSA#/GPO1,SUSB#/ GPO2,SUSC#,
			SUSST1#/GPO3,SUSCLK /GPO4,GPI1,GPI2/EXTSMI#,GPI3
			/RING#,GPI4 /LID,GPI5 /BATLOW#,GPI6 /PME#,
			SMBALRT#
VSUS25	T4,U4	P	Suspend Power.2.5V ±5%.
VSUSUSB	D15	P	USB Suspend Power.2.5V ±5%.
VBAT	AE4	P	RTC Battery. Battery input for internal RTC
			(RTCX1,RTCX2)
VLVREF	J23	P	V-Link Voltage Reference.0.9V ±5%.0.34 xVCC25to0.38
			xVCC25.
VCCVK	(see pin list)	P	V-Link Compensation Circuit Voltage.2.5V ±5%
MIIVCC	D11,D12,	P	LAN MII Power.3.3V ±5%.Power for LAN Media
	E11,E12		Independent Interface (interface to external PHY).Connect o
			VCC33 through a ferrite bead.
MIIVCC25	D13,E13	P	LAN MII Suspend Power.2.5V ±5%.
RAMVCC	E7	P	LAN RAM Power.2.5V ±5%.Power for LAN internal RAM.
			Connect to VCC through a ferrite bead.
RAMGND	E8	P	LAN RAM Ground. Connect o GND through a ferrite bead.
USBVCC	(see pin list)	P	USB 2.0 Differential Output Power.3.3V ±5%.Power for
			USB differential outputs (USBP0+,P0 –,P1+,P1 –,P2+,
			P2 –, P3+, P3 –,P4+,P4 –,P5+,P5 –).Connect o VSUS33
			through a ferrite bead.
USBGND	(see pin list)	P	USB 2.0 Differential Output Ground. Connect to GND
			through a ferrite bead.

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