ISA-to-PC-Card (PCMCIA) Controllers — PD6710/’22
Low-Power Dynamic mode is transparent to the ISA bus. After reset, the PD67XX is configured
for Low-Power Dynamic mode. This mode can be turned off by setting Misc Control 2 register,
bit 1 to ‘0’. When in Low-Power Dynamic mode, periods of inactivity (no activity on the PC Card
bus and system accesses to chip registers or inserted cards are no longer being performed) cause
the PD67XX to enter a low-power state where the clock is turned off to most of the chip and the PC
Card address and data lines are set to a static value. VCC and VPP power to the card is left
unchanged. When there is activity present on the PC Card bus, or the system accesses PD67XX
registers, or PC Cards are inserted or removed from the socket, the PD67XX enters its active state,
services the transaction, and then returns to its low-power state.
A Suspend mode can also be programmed. The PD67XX Suspend mode is the chip’s lowest
software-controlled power mode. The PD67XX is put into Suspend mode by setting the Misc
Control 2 register, bit 2 to ‘1’. In Suspend mode, all the internal clocks are turned off, and only
read/write access to the Index register and write access to the Misc Control 2 register is supported.
All accesses to the PC Cards are ignored when in Suspend mode. VCC and VPP power to the card is
left unchanged (the system power management software is responsible for turning off power to the
socket and entering Suspend mode). Interrupts and ring indicate signals are passed through to the
system bus when in Suspend mode. To exit Suspend mode, the Misc Control 2 register bit 2 must
be reset to ‘0’. It requires 50 ms for the PD67XX to restart the internal clock synthesizer and
become active again.
In addition to the software suspend, if the system hold’s the AEN signal of the PD67XX high, a
hardware-assisted Super-Suspend mode occurs where ISA inputs to the chip are internally shut off.
Internal in the PD67XX, the ISA inputs are ignored and floating conditions on the ISA bus will not
cause high current flow in the PD67XX ISA input receivers. Since the ISA bus inputs to the core
logic of the PD67XX are also not toggling when AEN is set high, power consumption is further
reduced. Interrupts and ring indicate signals are passed through to the system bus when in Super-
Suspend mode
The PD67XX power can be further managed by controlling socket power as outlined in “Socket
Power Management Features” on page 34. Socket power can be turned on and off through software
or automatically when cards are inserted or removed. The PD67XX provides six pins per socket for
controlling external logic to switch VCC and VPP voltages on and off and for sensing a card’s
operating voltage range. Cards can be turned off when not in use.
Datasheet
33
INTEL [ INTEL ]
