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of their respective companies.
The AMD Geode™ SC2200 processor is a member of the
AMD Geode processor family of fully integrated x86 system
chips. The SC2200 processor includes:
• The Geode GX1 processor module combines advanced
CPU performance with MMX™ support, fully accelerated 2D graphics, a 64-bit synchronous DRAM
(SDRAM) interface, a PCI bus controller, and a display
controller.
• A low-power CRT and TFT Video Processor module with
a Video Input Port (VIP), and a hardware video accelerator for scaling, filtering, and color space conversion.
• The Core Logic module includes: PC/AT functionality, a
USB interface, an IDE interface, a PCI bus interface, an
LPC bus interface, Advanced Configuration Power Interface (ACPI) version 1.0 compliant power management,
and an audio codec interface.
• The SuperI/O module has: three Serial Ports (UART1,
UART2, and UART3 with fast infrared), a Parallel Port,
two ACCESS.bus (ACB) interfaces, and a Real-Time
Clock (RTC).
These features, combined with the device’s low power consumption, enable a small form factor design making it ideal
as the core for a thin client application.
1
GX1
CPU
Core
IDE I/F
USB
PCI/Sub-ISA
Bus I/F
GPIO
Audio Codec I/F
LPC I/F
Memory Controller
2D Graphics
Accelerator
PCI Bus
Controller
Display
Controller
Fast-PCI Bus
Bridge
PCI Bus
X-Bus
Config.
Block
Fast X-Bus
Core Logic
PIT
PIC
DMAC
Pwr Mgmnt
Configuration
ISA Bus I/F
Figure 1-1 shows the relationships between the modules.
Video Processor
CRT I/F
RTC
I/F
Video
Mixer
Clock & Reset Logic
TFT I/F
Parallel
Por t
ACB1
I/F
ACB2
I/F
UART1
UART2
UART3
& IR
Video
Scaling
Video Input Port (VIP)
Host Interface
SuperI/O
ISA Bus
Figure 1-1. Block Diagram
AMD Geode™ SC2200 Processor Data Book13
1.2Features
32580B
Overview
General Features
■ 32-Bit x86 processor, up to 300 MHz, with MMX
instruction set support
■ Memory controller with 64-bit SDRAM interface
■ 2D graphics accelerator
■ CRT controller with hardware video accelerator
■ CCIR-656 video input port with direct video for full
screen display
■ PC/AT functionality
■ PCI bus controller
■ IDE interface, two channels
■ USB, three ports, OHCI (OpenHost Controller Interface)
version 1.0 compliant
■ Audio, AC97/AMC97 version 2.0 compliant
■ Virtual System Architecture™ (VSA) technology support
■ Power management, ACPI (Advanced Configuration
Power Interface) version 1.0 compliant
■ Package:
— BGU481 (481-Terminal Ball Grid Array Cavity Up)
GX1 Processor Module
■ CPU Core:
— 32-Bit x86, 300 MHz, with MMX compatible instruc-
tion set support
— 16 KB unified L1 cache
— Integrated FPU (Floating Point Unit)
— Re-entrant SMM (System Management Mode)
enhanced for VSA
■ 2D Graphics Accelerator:
— Accelerates BitBLTs, line draw and text
— Supports all 256 raster operations
— Supports transparent BLTs
— Runs at core clock frequency
■ Memory Controller:
— 64-Bit SDRAM interface
— 66 MHz to 100 MHz frequency range
— Direct interface with CPU/cache, display controller
and 2D graphic accelerator
— Supports clock suspend and power-down/
self-refresh
— Up to two banks of SDRAM (8 devices total) or one
SODIMM
■ Display Controller:
— Hardware graphics frame buffer compress/
decompress
— Hardware cursor, 32x32 pixels
Video Processor Module
■ Video Accelerator:
— Flexible video scaling support of up to 8x
(horizontally and vertically)
— Bilinear interpolation filters (with two taps, and eight
phases) to smooth output video
■ Video/Graphics Mixer:
— 8-bit value alpha blending
— Three blending windows with constant alpha value
— Color key
■ Video Input Port (VIP):
— Video capture or display
— CCIR-656 and VESA Video Interface Port v1.1
compliant
— Lock display timing to video input timing (GenLock)
— Able to transfer video data into main memory
— Direct video transfer for full screen display
— Separate memory location for VBI
■ CRT Interface:
— Uses three 8-bit DACs
— Supports up to 135 MHz
— 1280x1024 non-interlaced CRT @ 8 bpp, up to 75 Hz
— 1024x768 non-interlaced CRT @ 16 bpp, up to 85 Hz
■ TFT Interface:
— Direct connection to TFT panels
— 800x600 non-interlaced TFT @ 16 bpp graphics,
up to 85 Hz
— 1024x768 non-interlaced TFT @ 16 bpp graphics,
up to 75 Hz
— TFT on IDE: FPCLK max is 40 MHz
— TFT on Parallel Port: FPCLK max is 80 MHz
Core Logic Module
■ Audio Codec Interface:
— AC97/AMC97 (Rev. 2.0) codec interface
— Six DMA channels
— ACPI v1.0 compliant
— Sx state control of three power planes
— Cx/Sx state control of clocks and PLLs
— Thermal event input
— Wakeup event support:
– Three general-purpose events
– AC97 codec event
– UART2 RI# signal
– Infrared (IR) event
14AMD Geode™ SC2200 Processor Data Book
Overview
32580B
■
General Purpose I/Os (GPIOs):
— 27 multiplexed GPIO signals
■ Low Pin Count (LPC) Bus Interface:
— Specification v1.0 compatible
■ PCI Bus Interface:
— PCI v2.1 compliant with wakeup capability
— 32-Bit data path, up to 33 MHz
— Glueless interface for an external PCI device
— Fixed priority
— 3.3V signal support only
■ Sub-ISA Bus Interface:
— Up to 16 MB addressing
— Supports a chip select for ROM or Flash EPROM
boot device
— Supports either:
– M-Systems DiskOnChip DOC2000 Flash file
system
– NAND EEPROM
— Supports up to two chip selects for external I/O
devices
— 8-Bit (optional 16-bit) data bus width
— Shares balls with PCI signals
— Is not a subtractive agent
■ IDE Interface:
— Two IDE channels for up to four external IDE devices
— Supports ATA-33 synchronous DMA mode transfers,
pins), used for SmartCard interface
— UART2, 16550A compatible
— Enhanced UART with fast Infrared (IR)
AMD Geode™ SC2200 Processor Data Book15
32580B
Overview
16AMD Geode™ SC2200 Processor Data Book
Architecture Overview32580B
2.0Architecture Overview
2
As illustrated in Figure 1-1 on page 13, the SC2200 processor contains the following modules in one integrated
device:
• GX1 Module:
— Combines advanced CPU performance with MMX
support, fully accelerated 2D graphics, a 64-bit
synchronous DRAM (SDRAM) interface and a PCI
bus controller. Integrates GX1 silicon revision 8.1.1.
• Video Processor Module:
— A low-power CRT and TFT support module with a
video input port, and a hardware video accelerator
for scaling, filtering and color space conversion.
• Core Logic Module:
— Includes PC/AT functionality, an IDE interface, a
Universal Serial Bus (USB) interface, ACPI 1.0
compliant power management, and an audio codec
interface.
• SuperI/O Module:
— Includes two Serial Ports, an Infrared (IR) Port, a
Parallel Port, two ACCESS.bus interfaces, and a
Real-Time Clock (RTC).
2.1GX1 Module
The GX1 processor (silicon revision 8.1.1) is the central
module of the SC2200. For detailed information regarding
the GX1 module, refer to the AMD Geode™ GX1 Proces-
sor Data Book and the AMD Geode™ GX1 Processor Silicon Revision 8.1.1 Specification Update document.
The device ID of the SC2200 processor is contained in the
GX1 module. Software can detect the revision by reading
the DIR0 and DIR1 Configuration registers (see Configuration registers in the AMD Geode™ GX1 Processor Data
Book). The AMD Geode™ SC2200 Processor Specification Update document contains the specific values.
2.1.1Memory Controller
The GX1 module is connected to external SDRAM devices.
For more information see Section 3.4.2 "Memory Interface
Signals" on page 54, and the “Memory Controller” chapter
in the AMD Geode™ GX1 Processor Data Book.
There are some differences in the memory controller of the
SC2200 processor and the standalone GX1 processor’s
memory controller:
1)There is drive strength/slew control in the SC2200 that
is not in the GX1. The bits that control this function are
in the MC_MEM_CNTRL1 and MC_MEM_CNTRL2
registers. In the GX1 processor, these bits are marked
as reserved.
2)The SC2200 supports two banks of memory. The GX1
supports four banks of memory. In addition, the
SC2200 supports a maximum of eight devices and the
GX1 supports up to 32 devices. With this difference,
the MC_BANK_CFG register is different.
Table 2-1 summarizes the 32-bit registers contained in the
SC2200’s memory controller. Table 2-2 gives detailed register/bit formats.
Staggering is used to help reduce power spikes during refresh by refreshing one bank at a time. If only one bank is installed,
this field must be written as 00.
52CLKADDR (Two Clock Address Setup). Assert memory address for one extra clock before CS# is asserted.
0: Disable.
1: Enable.
This can be used to compensate for address setup at high frequencies and/or high loads.
4RFSHTST (Test Refresh). This bit, when set high, generates a refresh request. This bit is only used for testing purposes.
3XBUSARB (X-Bus Round Robin). When round robin is enabled, processor, graphics pipeline, and low priority display con-
troller requests are arbitrated at the same priority level. When disabled, processor requests are arbitrated at a higher priority
level. High priority Display Controller requests always have the highest arbitration priority.
0: Disable.
1: Enable round robin.
2SMM_MAP (SMM Region Mapping). Maps the SMM memory region at GX_BASE+400000 to physical address A0000 to
BFFFF in SDRAM.
0: Disable.
1: Enable.
1RSVD (Reserved). Write as 0.
0SDRAMPRG (Program SDRAM). When this bit is set, the memory controller will program the SDRAM MRS register using
LTMODE in MC_SYNC_TIM1.
This bit must transition from zero (written to zero) to one (written to one) in order to program the SDRAM devices.
30:28LTMODE (CAS Latency). CAS latency is the delay, in SDRAM clock cycles, between the registration of a read command
27:24RC (RFSH to RFSH/ACT Command Period, tRC). Minimum number of SDRAM clock between RFSH and RFSH/ACT
23:20RAS (ACT to PRE Command Period, tRAS). Minimum number of SDRAM clocks between ACT and PRE commands:
18:16RP (PRE to ACT Command Period, tRP). Minimum number of SDRAM clocks between PRE and ACT commands:
14:12RCD (Delay Time ACT to READ/WRT Command, tRCD). Minimum number of SDRAM clock between ACT and READ/
and the availability of the first piece of output data. This parameter significantly affects system performance. Optimal setting
should be used. If an SODIMM is used, BIOS can interrogate EEPROM across the ACCESS.bus interface to determine this
value:
10:8RRD (ACT(0) to ACT(1) Command Period, tRRD). Minimum number of SDRAM clocks between ACT and ACT command
to two different component banks within the same module bank. The memory controller does not perform back-to-back Activate commands to two different component banks without a READ or WRITE command between them. Hence, this field
should be written as 001.
7RSVD (Reserved). Write as 0.
6:4DPL (Data-in to PRE command period, tDPL). Minimum number of SDRAM clocks from the time the last write datum is
3:0RSVD (Reserved). Leave unchanged. Always returns a 101h.
Note:Refer to the SDRAM manufacturer’s specification for more information on component banks.
0: TEST[3:0] are driven low (normal operation).
1: TEST[3:0] pins are used to output test information.
16TECTL (Test Enable Shared Control Pins).
0: RASB#, CASB#, CKEB, WEB# (normal operation).
1: RASB#, CASB#, CKEB, WEB# are used to output test information.
11RSVD (Reserved). Write as 0.
KB boundaries. This field corresponds to address bits [29:19].
Note that BC_DRAM_TOP must be set to a value lower than the Graphics Base Address.
register. This field does not auto increment.
1D (Dirty Bit). This bit is read/write accessible.
0V (Valid Bit). This bit is read/write accessible.
AMD Geode™ SC2200 Processor Data Book21
32580B
Architecture Overview
2.1.2Fast-PCI Bus
The GX1 module communicates with the Core Logic module via a Fast-PCI bus that can work at up to 66 MHz. The
Fast-PCI bus is internal for the SC2200 and is connected to
the General Configuration Block (see Section 4.0 on page
75 for details on the General Configuration Block).
This bus supports seven bus masters. The requests
(REQs) are fixed in priority. The seven bus masters in order
of priority are:
1)VIP
2)IDE Channel 0
3)IDE Channel 1
4)Audio
5)USB
6)External REQ0#
7)External REQ1#
2.1.3Display
The GX1 module generates display timing, and controls
internal signals CRT_VSYNC and CRT_HSYNC of the
Video Processor module.
The GX1 module interfaces with the Video Processor via a
video data bus and a graphics data bus.
• Video data. The GX1 module uses the core clock,
divided by 2 or 4 (typically 100 - 133 MHz). It drives the
video data using this clock. Internal signals VID_VAL
and VID_RDY are used as data-flow handshake signals
between the GX1 module and the Video Processor.
• Graphics data. The GX1 module uses the internal
signal DCLK, supplied by the PLL of the Video
Processor, to drive the 18-bit graphics-data bus of the
Video Processor. Each six bits of this bus define a
different color. Each of these 6-bit color definitions is
expanded (by adding two zero LSB lines) to form an
8-bit bus, at the Video Processor.
For more information about the GX1 module’s interface to
the Video Processor, see the “Display Controller” chapter
in the AMD Geode™ GX1 Processor Data Book.
2.2Video Processor Module
The Video Processor provides high resolution and graphics
for a CRT or TFT/DSTN interface. The following subsections provide a summary of how the Video Processor interfaces with the other modules of the SC2200. For detailed
information about the Video Processor, see Section 7.0
"Video Processor Module" on page 319.
2.2.1GX1 Module Interface
The Video Processor is connected to the GX1 module in
the following way:
• The Video Processor’s DOTCLK output signal is used as
the GX1 module’s DCLK input signal.
• The GX1 module’s PCLK output signal is used as the
GFXCLK input signal of the Video Processor.
2.2.2Video Input Port
The Video Input Port (VIP) within the Video Processor contains a standard interface that is typically connected to a
media processor or TV encoder. The clock is supplied by
the externally connected device; typically at 27 MHz.
Video input can be sent to the GX1 module’s video frame
buffer (Capture Video mode) or can be used directly (Direct
Video mode).
2.2.3Core Logic Module Interface
The Video Processor interfaces to the Core Logic module
for accessing PCI function configuration registers.
2.2.4CRT DAC
The Video Processor drives three CRT DACs with up to
135M pixels per second.
The interface for these DACs can be monitored via external
balls of the SC2200. For more information, see Section
3.4.4 "CRT/TFT Interface Signals" on page 56.
22AMD Geode™ SC2200 Processor Data Book
Architecture Overview
32580B
2.3Core Logic Module
The Core Logic module is described in detail in Section 6.0
"Core Logic Module" on page 149.
The Core Logic module is connected to the Fast-PCI bus. It
uses signal AD28 as the IDSEL for all PCI configuration
functions except for USB which uses AD29.
2.3.1Other Interfaces of the Core Logic
Module
The following interfaces of the Core Logic module are
implemented via external balls of the SC2200. Each interface is listed below with a reference to the descriptions of
the relevant balls.
• IDE: See Section 3.4.9 "IDE Interface Signals" on page
63.
• AC97: See Section 3.4.14 "AC97 Audio Interface
Signals" on page 68.
• PCI: See Section 3.4.6 "PCI Bus Interface Signals" on
page 57.
• USB: See Section 3.4.10 "Universal Serial Bus (USB)
Interface Signals" on page 64. The USB function uses
signal AD29 as the IDSEL for PCI configuration.
• LPC: See Section 3.4.8 "Low Pin Count (LPC) Bus Inter-
face Signals" on page 62.
• Sub-ISA: See Section 3.4.7 "Sub-ISA Interface Signals"
on page 61, Section 6.2.5 "Sub-ISA Bus Interface" on
page 155, and Section 4.2 "Multiplexing, Interrupt Selection, and Base Address Registers" on page 76
• GPIO: See Section 3.4.16 "GPIO Interface Signals" on
page 70.
• More detailed information about each of these interfaces
is provided in Section 6.2 "Module Architecture" on page
150.
• Super/IO Block Interfaces: See Section 4.2 "Multi-
plexing, Interrupt Selection, and Base Address Registers" on page 76, Section 3.4.5 "ACCESS.bus Interface
Signals" on page 57, Section 3.4.13 "Fast Infrared (IR)
Port Interface Signals" on page 67, and Section 3.4.12
"Parallel Port Interface Signals" on page 66.
The Core Logic module interface to the GX1 module consists of seven miscellaneous connections, the PCI bus
interface signals, plus the display controller connections.
Note that the PC/AT legacy signals NMI, WM_RST, and
A20M are all virtual functions executed in SMM (System
Management Mode) by the BIOS.
• PSERIAL is a one-way serial bus from the GX1 to the
Core Logic module used to communicate powermanagement states and VSYNC information for VGA
emulation.
• IRQ13 is an input from the GX1 module indicating that a
floating point error was detected and that INTR should
be asserted.
• INTR is the level output from the integrated 8259A PICs
and is asserted if an unmasked interrupt request (IRQn)
is sampled active.
• SMI# is a level-sensitive interrupt to the GX1 module
that can be configured to assert on a number of different
system events. After an SMI# assertion, SMM is entered
and program execution begins at the base of the SMM
address space. Once asserted, SMI# remains active
until the SMI source is cleared.
• SUSP# and SUSPA# are handshake signals for implementing CPU Clock Stop and clock throttling.
• CPU_RST resets the CPU and is asserted for approximately 100 µs after the negation of POR#.
• PCI bus interface signals.
2.4SuperI/O Module
The SuperI/O (SIO) module is PC98 and ACPI compliant. It
offers a single-cell solution to the most commonly used ISA
peripherals.
The SIO module incorporates: two Serial Ports, an Infrared
Communication Port that supports FIR, MIR, HP-SIR,
Sharp-IR, and Consumer Electronics-IR, a full IEEE 1284
Parallel Port, two ACCESS.bus Interface (ACB) ports, System Wakeup Control (SWC), and a Real-Time Clock (RTC)
that provides RTC timekeeping.
AMD Geode™ SC2200 Processor Data Book23
32580B
Architecture Overview
2.5Clock, Timers, and Reset Logic
In addition to the four main modules (i.e., GX1, Core Logic,
Video Processor and SIO) that make up the SC2200, the
following blocks of logic have also been integrated into the
SC2200:
• Clock Generators as described in Section 4.5 "Clock
Generators and PLLs" on page 87.
• Configuration Registers as described in Section 4.2
"Multiplexing, Interrupt Selection, and Base Address
Registers" on page 76.
• A WATCHDOG timer as described in Section 4.3
"WATCHDOG" on page 83.
• A High-Resolution timer as described in Section 4.4
"High-Resolution Timer" on page 85.
2.5.1Reset Logic
This section provides a description of the reset flow of the
SC2200.
2.5.1.1Power-On Reset
Power-on reset is triggered by assertion of the POR# signal. Upon power-on reset, the following things happen:
• Strap balls are sampled.
• PLL4, PLL5, and PLL6 are reset, disabling their output.
When the POR# signal is negated, the clocks lock and
then each PLL outputs its clock. PLL6 is the last clock
generator to output a clock. See Section 4.5 "Clock
Generators and PLLs" on page 87.
• Certain WATCHDOG and High-Resolution Timer
register bits are cleared.
2.5.1.2System Reset
System reset causes signal PCIRST# to be issued, thus
triggering a reset of all PCI and LPC agents. A system
reset is triggered by any of the following events:
• Power-on, as indicated by POR# signal assertion.
• A WATCHDOG reset event (see Section 4.3.2
"WATCHDOG Registers" on page 84).
• Software initiated system reset.
24AMD Geode™ SC2200 Processor Data Book
Signal Definitions32580B
3.0Signal Definitions
3
This section defines the signals and describes the external
interface of the SC2200 processor. Figure 2-1 shows the
signals organized by their functional groups. Where signals
are multiplexed, the default signal name is listed first and is
The remaining subsections of this chapter describe:
• Section 3.1 "Ball Assignments": Provides a ball assignment diagram and tables listing the signals sorted
according to ball number and alphabetically by signal
name.
• Section 3.2 "Strap Options": Several balls are read at
power-up that set up the state of the SC2200. This
section provides details regarding those balls.
• Section 3.4 "Signal Descriptions": Detailed descriptions
of each signal according to functional group.
Signal Definitions
3.1Ball Assignments
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 signals 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 indicated 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
Notes:
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.
32580B
Table 3-1. Signal Definitions Legend
MnemonicDefinition
AAnalog
AV
SS
AV
CC
GCBGeneral Configuration Block registers.
IInput ball
I/OBidirectional ball
MCR[x]Miscellaneous Configuration Register
OOutput ball
ODOpen-drain
PDPull-down in KΩ
PMR[x]Pin Multiplexing Register Bit x: A regis-
PUPull-up in KΩ
TSTRI-STATE
V
CORE
V
IO
V
SS
#The # symbol in a signal name indicates
/A / in a signal name indicates both func-
+A + in signal name indicates the function
Ground ball: Analog
Power ball: Analog
Refer to Section 4.0 "General Configuration Block" on page 75.
Location of the General Configuration
Block cannot be determined by software.
See the AMD Geode™ SC2200 Proces-
sor Specification Update.
Bit x: A register, located in the GCB.
Refer to Section 4.1 "Configuration
Block Addresses" on page 75 for further
details.
ter, located in the GCB, used to configure balls with multiple functions. Refer to
Section 4.1 "Configuration Block
Addresses" on page 75 for further
details.
Power ball: 1.2V
Power ball: 3.3V
Ground ball
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.
tions are always enabled (i.e., cycle multiplexed).
is available on the ball, but that either
strapping options or register programming is required to select the desired
function.