XR17C158 Exar Corporation, XR17C158 Datasheet - Page 8

• Manufacturer Part Number: XR17C158
• Description: Eight-channel Pci-based (UART)
• Manufacturer: Exar Corporation

PRELIMINARY
ded inside the device configuration registers space,
which provides faster access. The following para-
graphs describe all 3 sets of registers in detail.
The PCI local bus configuration space registers are
responsible for setting up the device’s operating en-
vironment in the PCI local bus. The pre-defined oper-
ating parameters of the device is read by the PCI bus
plug-and-play auto-configuration manager in the op-
erating system. After the PCI bus has collected all da-
ta from every device/card on the bus, it defines and
F
1.1 PCI LOCAL BUS CONFIGURATION SPACE
IGURE
REGISTERS
Device Configuration and
Registers are mapped on
UART[7:0] Configuration
byte of memory address
Register (BAR) in a 4K-
3. T
PCI Local Bus
to the Base Address
Interface
HE
space
XR17C158 R
EGISTER
S
ETS
Configuration Space
Registers for Plug-
PCI Local Bus
and-Play Auto
TIMER, REG
Configuration
Channel 0
Channel 0
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
INT, MPIO,
8
downloads the memory mapping information to each
device/card about their individual operation memory
address location and conditions. The operating mem-
ory mapped address location is downloaded into the
Base Address Register (BAR) register, 0x10. The
plug-and-play auto configuration feature is only avail-
able when an external 93C46 EEPROM is used. The
EEPROM contains the device vendor and sub-vendor
data required by the auto-configuration setup.
0x0000
0x0080
0x0200
0x0400
0x0600
0x0800
0x0C00
0x0A00
0x0E00
0x0FFF
PCI BUS OCTAL UART
and Product Model Number
Vendor and Sub-vendor ID
in External EEPROM
Device Configuration Registers
16550 Compatible and EXAR
Sleep, Reset, DVID, DREV
UART[7:0] Configuration
16-bit Timer/Counter,
8 channel Interrupts,
Enhanced Registers
Multipurpose I/Os,
Registers
PCIREGS-1
XR17C158
REV. 1.0.0