cl-ps6700 Cirrus Logic, Inc., cl-ps6700 Datasheet - Page 20

• Manufacturer Part Number: cl-ps6700
• Description: Low-power Pc Card Controller For The Cl-ps7111
• Manufacturer: Cirrus Logic, Inc.

CL-PS6700
Low-Power PC Card Controller
3.2 Power States
3.2.1 Active State
The Active State is the normal operating state entered whenever PC Card accesses are required. In this
state the PCLK input is active, the PSLEEP_L input is deasserted, and the Idle bit in the Power Manage-
ment register is cleared.
3.2.2 Idle State
Normally, Idle State is entered/exited dynamically in hardware (by CL-PS6700 control logic) transparent
to software. This method is invoked by setting the Enable Auto Idle Mode bit in the Power Management
register, and appears identical to the Active State, except that some internal clocks are gated off between
transactions to conserve power. The software can enter Idle State explicitly by setting the Idle mode. In
this case, access to the CL-PS6700 registers is supported, but PC Card accesses do not propagate to
the card and a read fail or write fail event can occur, which can generate an interrupt to the host.
3.2.3 Standby State
Standby State is the lowest power state in the system and is entered by asserting the PSLEEP_L input.
At least two (rising) clock edges are required after PSLEEP_L is asserted before the PCLK is shut off. In
the Standby State the CL-PS6700 core and system interface power can remain on, but consumes near
zero power (microwatts). If card transactions are queued in the CL-PS6700 when PSLEEP_L is asserted,
they are either aborted or continue until finished (requiring more than two clocks), depending on the set-
ting of bit 9 (Standby Request During Card Access) in the Power Management register.
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, N D A R
I R R U S
O G I C
O N F I D E N T I A L
E Q U I R E D
20
November 1997
FUNCTIONAL DESCRIPTION
PRELIMINARY DATA BOOK v1.0