cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 44

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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Signal Definitions
2.2.8.1
Functions listed in Table 2-9 are functions that may be assigned to specific GPIO balls. The “Ball No.” column gives the ball
that must be used if this function is selected, and the “GPIOx” column gives the GPIO that the function is associated with.
Function Name
32KHZ
AC_BEEP
DDC_SCL
DDC_SDA
LOW_BAT#
MFGPT0_C1
MFGPT0_C2
MFGPT0_RS
MFGPT1_C1
MFGPT1_C2
MFGPT1_RS
GPIO Functions and Recommended Usage
Ball
No.
C8
D3
D2
D2
D3
(Continued)
K3
E1
E2
A9
K3
A1
Table 2-9. GPIOx Available Functions Descriptions
GPIO[x]
GPIO27
GPIO25
GPIO11
GPIO1
GPIO6
GPIO5
GPIO3
GPIO4
GPIO5
GPIO1
GPIO6
Type
I/O
I/O
O
O
O
O
O
O
I
I
I
Description
32 kHz Clock. When invoked, this ball produces a buffered output
of the 32 kHz clock provided on the 32kHz XCI and XCO pins.
This option is invoked by selecting the AUX_OUT_2 option of
GPIO27. Note that since GPIO27 is in the Standby power domain,
the 32 kHz clock output will continue in Sleep and Standby states.
Legacy PC/AT Speaker Beep. Connect to codec’s PC_BEEP.
DDC Serial Clock. This is a “recommended use” for GPIO3,
because this is one of the few GPIOs that have a high drive capac-
ity, open-drain output. The serial clock function must be imple-
mented in software to support DDC monitors. There is no
dedicated DDC clock function within the CS5535.
DDC Serial Data. This is a “recommended use” for GPIO4,
because this is one of the few GPIOs that have a high drive capac-
ity, open-drain output. The serial data function must be imple-
mented in software to support DDC monitors. There is no
dedicated DDC data function within the CS5535.
Low Battery Detect. This is a “recommended use” for GPIO25 in
battery-powered systems. It is invoked by setting GPIO25 to the
AUX_IN mode. The signal is intended to be driven low by an exter-
nal circuit when the battery voltage falls below a preset value
(determined by the external circuit). It could be used to generate a
PME (interrupt) - connected to LowBat function in the Power Man-
agement Controller that would then de-assert WORKING and
WORK_AUX, if no software action is taken within a programmable
time.
Multi-Function General Purpose Counter #0 - Compare 1 Out.
An output from the counter that, when asserted, indicates the
counter has reached the conditions set up in the counter’s
Compare 1 registers.
Multi-Function General Purpose Counter #0 - Compare 2 Out.
An output from the counter that, when asserted, indicates the
counter has reached the conditions set up in the counter’s
Compare 2 registers.
Multi-Function General Purpose Counter #0 - Restart. An input
to the counter that causes it to be reset to initial conditions and
then to resume counting.
Multi-Function General Purpose Counter #1 - Compare 1 Out.
An output from the counter that, when asserted, indicates the
counter has reached the conditions set up in the counter’s
Compare 1 registers.
Multi-Function General Purpose Counter #1 - Compare 2 Out.
An output from the counter that, when asserted, indicates the
counter has reached the conditions set up in the counter’s
Compare 2 registers.
Multi-Function General Purpose Counter #1 - Restart. An input
to the counter that causes it to be reset to initial conditions and
then to resume counting.
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