User`s guide

Table 12 TV-Out Signal Descriptions

Signal Pin # Description I/O PU/PD Comment

TV_DAC_A B97 TVDAC Channel A Output supports the following: Composite video: CVBS

Component video: Chrominance (Pb) analog signal

S-Video: not used

O Analog Not supported

TV_DAC_B B98 TVDAC Channel B Output supports the following: Composite video: not used

Component video: Luminance (Y) analog signal.

S-Video: Luminance analog signal.

O Analog Not supported

TV_DAC_C B99 TVDAC Channel C Output supports the following: Composite video: not used

Component: Chrominance (Pr) analog signal.

S-Video: Chrominance analog signal.

O Analog Not supported

Table 13 Miscellaneous Signal Descriptions

Signal Pin # Description I/O PU/PD Comment

I2C_CK B33 General purpose I²C port clock output/input I/O 3.3V PU 4k7 3.3V

I2C_DAT B34 General purpose I²C port data I/O line I/O 3.3V PU 4k7 3.3V

SPKR B32 Output for audio enunciator, the “speaker” in PC-AT systems O 3.3V SPEAKER is a boot strap signal

(see note below)

BIOS_DISABLE# A34 Module BIOS disable input. Pull low to disable module BIOS. Used to allow off-

module BIOS implementations.

I 3.3V PU 4k7 3.3V

WDT B27 Output indicating that a watchdog time-out event has occurred. O 3.3V PU 10k 3.3V

KBD_RST# A86 Input to module from (optional) external keyboard controller that can force a

reset. Pulled high on the module. This is a legacy artifact of the PC-AT.

KBD_A20GATE A87 Input to module from (optional) external keyboard controller that can be used to

control the CPU A20 gate line. The A20GATE restricts the memory access to the

bottom megabyte and is a legacy artifact of the PC-AT. Pulled low on the module.

Note

Some signals have special functionality during the reset process. They may bootstrap some basic important functions of the module. For more

information refer to section 7.5 of this user’s guide.