ISA-to-PC-Card (PCMCIA) Controllers — PD6710/’22
Bit 0 — Bypass Frequency Synthesizer
0
1
Normal operation, internal clock = CLK input frequency x 7/4.
Internal clock = CLK input frequency (see Table 1).
This bit determines internal time base.
Bit 1 — Low-Power Dynamic Mode
0
1
Clock runs always.
Normal operation, stop clock when possible.
This bit determines whether Low-Power Dynamic mode is enabled. For maximum operational
power savings, keep this bit set to ‘1’.
Bit 2 — Suspend
0
1
Normal operation.
Stop Frequency Synthesizer, enable all Low-Power modes and disable socket access.
This bit enables Suspend mode. After entering Suspend, AEN should be pulled high for lowest
power consumption. When this bit is high and AEN is high, all ISA bus interface inputs are turned
off. In 82386SL systems when the processor is in Suspend mode, the ISA bus interface signals
float; this feature will prevent high current flow in the PD67XX inputs.
Bit 3 — 5V Core
0
1
Normal operation: use when CORE_VDD pin is connected to 3.3 volts.
Selects input thresholds for use when 5.0 volts is connected to the PD67XX CORE_VDD pins.
This bit selects input threshold circuits for use when 3.3 or 5.0 volts is connected to the PD67XX
CORE_VDD pins. This bit must be set to ‘0’ when the CORE_VDD pins are connected to 3.3 volts
to preserve TTL-compatible input thresholds to the card socket.
Bit 4 — Drive LED Enable
0
1
IRQ12 operates normally.
IRQ12 becomes an open-drain output suitable for driving an LED (driven whenever the card -
SPKR output is turned on, and the corresponding Speaker Is LED input bit (see “Bit 1 —
Speaker Is LED Input” on page 76) is set).
Note: This bit should be set to ‘0’ if in Memory Card Interface mode. This bit determines whether -SPKR
is used to drive an LED on the IRQ12 ( Table 1) for disk drives.
Datasheet
73
INTEL [ INTEL ]
