32580B

Signal Definitions

3.4Signal Descriptions

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

3.4.1System Interface

Signal Name

Ball No.

Type

Description

Mux

 

 

 

 

 

CLKSEL1

AF3

I

Fast-PCI Clock Selects. These strap signals are used to

SOUT1

 

 

 

set the internal Fast-PCI clock.

 

CLKSEL0

B8

 

RD#

 

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

 

 

 

 

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

 

 

 

 

resistor of 1.5 KΩ must be used.

 

 

 

 

 

 

CLKSEL3

P30

I

Maximum Core Clock Multiplier. These strap signals

SYNC

 

 

 

are used to set the maximum allowed multiplier value for

 

CLKSEL2

D29

 

SOUT2

 

the core clock.

 

 

 

 

 

 

 

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

 

 

 

 

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

 

 

 

 

resistor of 1.5 KΩ must be used.

 

 

 

 

 

 

BOOT16

C8

I

Boot ROM is 16 Bits Wide. This strap signal enables

ROMCS#

 

 

 

the optional 16-bit wide Sub-ISA bus.

 

 

 

 

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

 

 

 

 

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

 

 

 

 

resistor of 1.5 KΩ must be used.

 

 

 

 

 

 

LPC_ROM

D6

I

LPC_ROM. This strap signal forces selecting of the LPC

PCICLK1

 

 

 

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

 

 

 

 

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

 

 

 

 

resistor of 1.5 KΩ must be used.

 

 

 

 

 

 

TFT_PRSNT

P29

I

TFT Present. A strap used to select multiplexing of TFT

SDATA_OUT

 

 

 

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

 

 

 

 

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

 

 

 

 

resistor of 1.5 KΩ must be used.

 

 

 

 

 

 

FPCI_MON

A4

I

Fast-PCI Monitoring. The strap on this ball forces selec-

PCICLK0

 

 

 

tion of Fast-PCI monitoring signals. For normal operation,

 

 

 

 

strap this signal low using a 1.5 KΩ resistor. The value of

 

 

 

 

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

 

 

 

 

 

 

DID1

C6

I

Device ID. Together, the straps on these signals define

GNT1#

 

 

 

the system-level chip ID.

 

DID0

C5

I

GNT0#

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 KΩ and DID1

 

 

 

 

must have a pull-down resistor of 1.5 KΩ.

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

 

 

 

 

52

 

 

AMD Geode™ SC2200 Processor Data Book

Page 48
Image 48
AMD SC2200 manual Signal Descriptions, System Interface, Signal Name Ball No Type Description Mux