beautypg.com

4 signal descriptions, 1 system interface, Section 3.4 "signal descriptions – AMD Geode SC2200 User Manual

Page 48

background image

52

AMD Geode™ SC2200 Processor Data Book

Signal Definitions

32580B

3.4

Signal Descriptions

Information in the tables that follow may have duplicate information in multiple tables. Multiple references all contain identi-
cal information.

3.4.1

System Interface

Signal Name

Ball No.

Type

Description

Mux

CLKSEL1

AF3

I

Fast-PCI Clock Selects. These strap signals are used to
set the internal Fast-PCI clock.

00 = 33.3 MHz
01 = 48 MHz
10 = 66.7 MHz
11 = 33.3 MHz

During system reset, an internal pull-down resistor of 100
K

Ω exists on these balls. An external pull-up or pull-down

resistor of 1.5 K

Ω must be used.

SOUT1

CLKSEL0

B8

RD#

CLKSEL3

P30

I

Maximum Core Clock Multiplier. These strap signals
are used to set the maximum allowed multiplier value for
the core clock.

During system reset, an internal pull-down resistor of 100
K

Ω exists on these balls. An external pull-up or pull-down

resistor of 1.5 K

Ω must be used.

SYNC

CLKSEL2

D29

SOUT2

BOOT16

C8

I

Boot ROM is 16 Bits Wide. This strap signal enables
the optional 16-bit wide Sub-ISA bus.

During system reset, an internal pull-down resistor of 100
K

Ω exists on these balls. An external pull-up or pull-down

resistor of 1.5 K

Ω must be used.

ROMCS#

LPC_ROM

D6

I

LPC_ROM. This strap signal forces selecting of the LPC
bus and sets bit F0BAR1+I/O Offset 10h[15], LPC ROM
Addressing Enable. It enables the SC2200 to boot from a
ROM connected to the LPC bus.

During system reset, an internal pull-down resistor of 100
K

Ω exists on these balls. An external pull-up or pull-down

resistor of 1.5 K

Ω must be used.

PCICLK1

TFT_PRSNT

P29

I

TFT Present. A strap used to select multiplexing of TFT
signals at power-up. Enables using TFT instead of Paral-
lel Port, ACB1, and GPIO17.

During system reset, an internal pull-down resistor of 100
K

Ω exists on these balls. An external pull-up or pull-down

resistor of 1.5 K

Ω must be used.

SDATA_OUT

FPCI_MON

A4

I

Fast-PCI Monitoring. The strap on this ball forces selec-
tion of Fast-PCI monitoring signals. For normal operation,
strap this signal low using a 1.5 K

Ω resistor. The value of

this strap can be read on the MCR[30].

PCICLK0

DID1

C6

I

Device ID. Together, the straps on these signals define
the system-level chip ID.

The value of DID1 can be read in the MCR[29]. The
value of DID0 can be read in the MCR[31].

DID0 must have a pull-up resistor of 1.5 K

Ω and DID1

must have a pull-down resistor of 1.5 K

Ω.

GNT1#

DID0

C5

I

GNT0#

POR#

AH9

I

Power On Reset. POR# is the system reset signal gen-
erated from the power supply to indicate that the system
should be reset.

---