BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
28
Section 3: System Overview
Document
1250_1125-UM100CB-R
12
ser0_enable
Serial port 0 is synchronous.
Serial port 0 is UART A.
Section: “Synchrono
us
Mode” on page 337
This sets the reset configuration, software may change it.
13
ser0_rstb_en
GPIO[0] is driven as
S0_RSTROBE by serial port 0.
GPIO[0] is a GPIO pin.
Section: “Synchrono
us
Mode” on page 337
14
ser1_enable
Serial port 1 is synchronous.
Serial port 1 is UART B.
Section: “Synchrono
us
Mode” on page 337
This sets the reset configuration, software may change it.
15
ser1_rstb_en
GPIO[1] is driven as
S1_RSTROBE by serial port 1.
GPIO[1] is a GPIO pin.
Section: “Synchrono
us
Mode” on page 337
16
pcmcia_enable
PCMCIA controller enabled.
GPIO[15:6] are used by the
PCMCIA logic.
IO_CS_L[6] is PCMCIA select.
PCMCIA controller disabled.
GPIO[15:6] are GPIO pins.
IO_CS_L[6] is a general
chip select.
Section: “Introductio
n” on page 422
17
boot_mode[0]
The IO_CS_L[0] region of the
generic bus space that is used
for the boot ROM is configured
for non-multiplexed operation
with 8 data bits and 24 address
bits.
The SMBus EEPROM boot is
configured for large (> 16 kbit)
EEPROMs using the eeprom
read word protocol.
The IO_CS_L[0] region of
the generic bus space that is
used for the boot ROM is
configured for multiplexed
operation with 32 data bits
and 32 address/enable bits.
The SMBus EEPROM boot
is configured for small (<=
16 kbit) EEPROMs using the
read word protocol.
Section: “Configurin
g a Chip Select
Region” on page 36
3
Section: “Booting
Using an SMBus
EEPROM” on page
413
18
boot_mode[1]
The boot address will access an
EEPROM on the SMBus.
The boot address will
access a ROM on the
generic bus.
Section: “Boot ROM
Support” on page 37
3
Section: “Booting
Using an SMBus
EEPROM” on page
413
19
pci_host
The PCI interface is run as the
host bridge.
The PCI interface is run as a
regular device.
Section: “Introductio
n” on page 190
.
20
pci_arbiter
The PCI interface uses the
internal arbiter. This must not be
set if bit [19] is pulled down.
The PCI interface uses an
external arbiter.
Section: “PCI
Arbiter” on page 222
.
21
southOnLDT
The South Bridge is on the
HyperTransport fabric or on a
bus bridged from the
HyperTransport fabric.
The South Bridge is on the
PCI bus.
Section: “The
SouthBridge, VGA
and Subtractive
Decode” on page 19
5
If there is no South Bridge this bit may be set either way.
22
big_endian
The system is Big Endian.
The system is Little Endian.
Section: “Introductio
n” on page 9
.
23
genclk_en
Enables output of the generic
bus clock on the IO_CLK100 pin.
Set the IO_CLK100 pin to a
high impedance state.
Section: “Generic
Bus
Timing” on page 365
.
Table 8: Static Configuration Options
(Cont.)
IO_AD
Bit
Name
Pulled Up to 3.3V
Pulled Down
Section