AMD SC2200 User Manual

32580B

The SC2200 is highly configurable as illustrated in Figure
3-1 on page 25. Strap options and register programming
are used to set various modes of operation and specific
signals on specific balls. This section describes which sig-
nals are available on which balls and provides configuration
information:

• Figure 3-2 on page 28: Illustrates the BGU481 ball 

assignments.

• Table 3-2 on page 29: Lists signals according to ball 

number. Power Rail, Signal Type, Buffer Type and, 
where relevant, Pull-Up or Pull-Down resistors are indi-
cated for each ball in this table. For multiplexed balls, the 
necessary configuration for each signal is listed as well.

•  Table 3-3 on page 41: Quick reference signal list sorted 

alphabetically - listing all signal names and ball 
numbers.The tables in this chapter use several common 
abbreviations. Table 3-1 lists the mnemonics and their 
meanings

1)

For each GPIO signal, there is an optional pull-up
resistor on the relevant ball. After system reset, the
pull-up is present.

This pull-up resistor can be disabled via registers in
the Core Logic module. The configuration is without
regard to the selected ball function (except for
GPIO12, GPIO13, and GPIO16). Alternate functions
for GPIO12, GPIO13, and GPIO16 control pull-up
resistors.

For more information, see Section 6.4.1 "Bridge,
GPIO, and LPC Registers - Function 0" on page 198.

2)

Configuration settings listed in this table are with
regard to the Pin Multiplexing Register (PMR). See
Section 4.2 "Multiplexing, Interrupt Selection, and
Base Address Registers" on page 76 for a detailed
description of this register.

A

Analog

AV

SS

Ground ball: Analog 

AV

CC

Power ball: Analog

GCB

General Configuration Block registers. 
Refer to Section 4.0 "General Configura-
tion Block" on page 75.

Location of the General Configuration 
Block cannot be determined by software. 
See the AMD Geode™ SC2200 Proces-
sor Specification Update.

I

Input ball

I/O

Bidirectional ball

MCR[x]

Miscellaneous Configuration Register 
Bit x: A register, located in the GCB. 
Refer to Section 4.1 "Configuration 
Block Addresses" on page 75 for further 
details.

O

Output ball

OD

Open-drain

PD

Pull-down in K

Ω

PMR[x]

Pin Multiplexing Register Bit x: A regis-
ter, located in the GCB, used to config-
ure balls with multiple functions. Refer to 
Section 4.1 "Configuration Block 
Addresses" on page 75 for further 
details.

PU

Pull-up in K

Ω

TS

TRI-STATE

V

CORE

Power ball: 1.2V

V

IO

Power ball: 3.3V

V

SS

Ground ball

#

The # symbol in a signal name indicates 
that the active or asserted state occurs 
when the signal is at a low voltage level. 
Otherwise, the signal is asserted when 
at a high voltage level.

/

A / in a signal name indicates both func-
tions are always enabled (i.e., cycle mul-
tiplexed).

+

A + in signal name indicates the function 
is available on the ball, but that either 
strapping options or register program-
ming is required to select the desired 
function.