Ac'97/hda codec, Lpc interface, Extended system management – Ampro Corporation XTX 820 User Manual

Page 37

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Chapter 3

Hardware

XTX 820

Reference Manual

31

AC'97/HDA CODEC

The additional signals provided by J2 support AC'97 digital audio CODECs as well HDA (High
Definition Audio) audio CODECs.

Table 3-12. Audio CODEC Interface Pin/Signal Descriptions (J2)

Pin #

Signal

Description

81

AC_RST*

AC'97/HDA CODEC Reset

85

AC_SYNC

AC'97/HDA Serial Bus Synchronization

89

AC_BIT_CLK

AC'97/HDA 12.228 MHz Serial Bit Clock from CODEC

82

AC_SDOUT

AC'97/HDA Audio Serial Data Output to CODEC

86

AC_SDIN0

AC'97/HDA Audio Serial Data Input from CODEC0

87

AC_SDIN1

AC'97/HDA Audio Serial Data Input from CODEC1

88

AC_SDIN2

AC'97/HDA Audio Serial Data Input from CODEC2

79

CODECSET

AC`97/HDA Disable onboard Audio CODEC

Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.

LPC Interface

The LPC (Low Pin Count) bus is provided as a replacement for the increasingly less often used ISA bus.
The LPC bus is used on PC-style personal computers to connect low-bandwidth devices to the CPU,
such as the boot ROM, "legacy" I/O devices (supported by a Super I/O chip), and audio controllers. The
"legacy" I/O devices usually include serial and parallel ports, keyboard, mouse, and a floppy disk
controller. Due to the software compatibility of the LPC bus to the ISA bus, I/O devices such as
additional serial ports can be easily implemented on an application specific baseboard using the LPC
bus. There are also many devices available for the LPC bus.

Table 3-13. LPC Interface Pin/Signal Descriptions (J2)

Pin #

Signal

Description

91

LPC_AD0

LPC Multiplexed Command, Address and Data Line 0

93

LPC_AD1

LPC Multiplexed Command, Address and Data Line 1

94

LPC_FRAME*

LPC Frame – Indicates start of a new or termination of a broken cycle.

95

LPC_AD2

LPC Multiplexed Command, Address and Data Line 2

96

LPC_DRQ0*

LPC Encoded DMA/Bus Master Request Line 0

97

LPC_AD3

LPC Multiplexed Command, Address and Data Line 3

98

LPC_DRQ1*

LPC Encoded DMA/Bus Master Request Line 1

Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.

Extended System Management

The Extended System Management interface, implemented by the Super I/O chip (W83627HG), provide
additional signals and functions to further improve system management. One of these signals is an
output signal called FAN_PMOUT that allows system fan control using a PWM (Pulse Width
Modulation) Output. Additionally there is an input signal called FAN_TACHOIN that provides the
ability to monitor the system fan's RPMs (revolutions per minute).

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