Texas Instruments Dual/Single Socket CardBus and UntraMedia Controller PCI7621 - Manual (Page 48)

2−22
Table 2−12. CardBus PC Card Interface System Terminals
A 33-
Ω
to 47-
Ω
series damping resistor (per PC Card specification) is the only external component needed for
terminals B08 (A_CCLK) and H17 (B_CCLK). If any CardBus PC Card interface system terminal is unused, then the
terminal may be left floating.
SKT A TERMINAL SKT B TERMINAL†
DESCRIPTION
I/O
INPUT OUTPUT
PU/ POWER
NAME NO. NAME NO.
DESCRIPTION
I/O
TYPE
INPUT OUTPUT
PU/
PD
POWER
RAIL
A_CCLK E09 B_CCLK H18
CardBus clock. CCLK provides synchronous timing
for all transactions on the CardBus interface. All
signals except CRST, CCLKRUN, CINT, CSTSCHG,
CAUDIO, CCD2, CCD1, CVS2, and CVS1 are
sampled on the rising edge of CCLK, and all timing
parameters are defined with the rising edge of this
signal. CCLK operates at the PCI bus clock
frequency, but it can be stopped in the low state or
slowed down for power savings.
O PCIO3
VCCA/
VCCB
A_CCLKRUN C03 B_CCLKRUN A18
CardBus clock run. CCLKRUN is used by a CardBus
PC Card to request an increase in the CCLK
frequency, and by the controller to indicate that the
CCLK frequency is going to be decreased.
I/O PCII4 PCIO4 PU3
VCCA/
VCCB
A_CRST A06 B_CRST F17
CardBus reset. CRST brings CardBus PC
Card-specific registers, sequencers, and signals to a
known state. When CRST is asserted, all CardBus
PC Card signals are placed in a high-impedance
state, and the controller drives these signals to a valid
logic level. Assertion can be asynchronous to CCLK,
but deassertion must be synchronous to CCLK.
O PCII4 PCIO4 PU3
VCCA/
VCCB
† These terminals are reserved for the PCI7611 and PCI7411 controllers.