![](http://datasheet.mmic.net.cn/330000/PCI6421_datasheet_16443878/PCI6421_53.png)
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3.5.2
Low Voltage CardBus Card Detection
The card detection logic of the PCI6x21/PCI6x11 controller includes the detection of Cardbus cards with V
CC
= 3.3 V
and V
PP
= 1.8 V. The reporting of the 1.8-V CardBus card (V
CC
= 3.3 V, V
PP
= 1.8 V) is reported through the socket
present state register as follows based on bit 10 (12V_SW_SEL) in the general control register (PCI offset 86h, see
Section 4.31):
If the 12V_SW_SEL bit is 0 (TPS2228 is used), then the 1.8-V CardBus card causes the 3VCARD bit in the
socket present state register to be set.
If the 12V_SW_SEL bit is 1 (TPS2226 is used), then the 1.8-V CardBus card causes the XVCARD bit in
the socket present state register to be set.
3.5.3
UltraMedia Card Detection
The PCI6x21/PCI6x11 controller is capable of detecting all the UltraMedia devices defined by the PCMCIA
Proposal
0262
– MultiMedia Cards, Secure Digital, Memory Stick devices, and Smart Card devices. The detection of these
devices is made possible through circuitry included in the PCI6x21/PCI6x11 controller and the adapters used to
interface these devices with the PC Card/CardBus sockets. No additional hardware requirements are placed on the
system designer in order to support these devices.
The
PC Card Standard
addresses the card detection and recognition process through an interrogation procedure that
the socket must initiate upon card insertion into a cold, unpowered socket. Through this interrogation, card voltage
requirements and interface type (16-bit vs. CardBus) are determined. The scheme uses the CD1, CD2, VS1, and VS2
signals (CCD1, CCD2, CVS1, CVS2 for CardBus). A PC Card designer connects these four terminals in a certain
configuration to indicate the type of card and its supply voltage requirements. The encoding scheme for this, defined
in the
PC Card Standard
, is shown in Table 31.
Table 31. PC Card—Card Detect and Voltage Sense Connections
CD2//CCD2
CD1//CCD1
VS2//CVS2
VS1//CVS1
Key
Interface
VCC
5 V
VPP/VCORE
Per CIS (VPP)
Per CIS (VPP)
Per CIS (VPP)
Ground
Ground
Open
Open
5 V
16-bit PC Card
Ground
Ground
Open
Ground
5 V
16-bit PC Card
5 V and 3.3 V
Ground
Ground
Ground
Ground
5 V
16-bit PC Card
5 V, 3.3 V, and
X.X V
Ground
Ground
Open
Ground
LV
16-bit PC Card
3.3 V
Per CIS (VPP)
Ground
Connect to
CVS1
Open
Connect to
CCD1
LV
CardBus PC Card
3.3 V
Per CIS (VPP)
Ground
Ground
Ground
Ground
LV
16-bit PC Card
3.3 V and X.X V
Per CIS (VPP)
Connect to
CVS2
Ground
Connect to
CCD2
Ground
LV
CardBus PC Card
3.3 V and X.X V
Per CIS (VPP)
Connect to
CVS1
Ground
Ground
Connect to
CCD2
LV
CardBus PC Card
3.3 V, X.X V,
and Y.Y V
Per CIS (VPP)
Ground
Ground
Ground
Open
LV
16-bit PC Card
X.X V
Per CIS (VPP)
Connect to
CVS2
Ground
Connect to
CCD2
Open
LV
CardBus PC Card
3.3 V
1.8 V (VCORE)
Ground
Connect to
CVS2
Connect to
CCD1
Open
LV
CardBus PC Card
X.X V and Y.Y V
Per CIS (VPP)
Connect to
CVS1
Ground
Open
Connect to
CCD2
LV
CardBus PC Card
Y.Y V
Per CIS (VPP)
Ground
Connect to
CVS1
Ground
Connect to
CCD1
LV
UltraMedia
Per query terminals
Ground
Connect to
CVS2
Connect to
CCD1
Ground
Reserved
Reserved