xr17v258 Exar Corporation, xr17v258 Datasheet - Page 13

• Manufacturer Part Number: xr17v258
• Description: 66mhz Pci Bus Octal Uart With Power Management Support
• Manufacturer: Exar Corporation

xr
REV. 1.0.0
D3
The V258 enters the state when power is removed from the device. All context is lost in this state and the V258
does not support PME# in this state. When power is restored, PCI RST# must be asserted and the V258 will
return to the D0 Uninitialized state with a full PCI 3.0 compliant power-on reset sequence. The V258 will set all
its registers and outputs to the power-on defaults just as at initial power up. The system software must then
fully initialize and re-configure the V258 to place it in the D0 Active state.
This 32-bit register can be used to store user information and is writable only via the EEPROM. This is
implemented at an offset of 0x48 in the PCI Configuration Space immediately following the Power
Management Registers. This register can be used to store application-specific information which may be used
by the device driver to initialize the device appropriately.
N
F
1.3
OTE
IGURE
A
COLD
O
DDRESS
0x48
FFSET
: EWR=Read/Write from external EEPROM.
S
4. P
Special Read/Write Register to store User Information
TATE
OWER
B
31:0
ITS
Active
S
Power on +
TATE
PCI RST#
D0
EWR
T
T
YPE
RANSITIONS OF THE
66MHZ PCI BUS OCTAL UART WITH POWER MANAGEMENT SUPPORT
T
ABLE
User Information Writable only through EEPROM
3: S
PECIAL
XR17V258
Uninitialized
D3
R
D0
13
EAD
hot
D
ESCRIPTION
/W
RITE
R
EGISTER
VCC Removed
Power on +
PCI RST#
D3
cold
R
0x00000000
ESET
XR17V258
(
HEX
V
ALUE
)