Notes:
1. The shared GPIO20–GPIO15, GPIO_CS14–GPIO_CS13, and PC Card battery signals:
As GPIO_CSxs, the signals are active in Suspend mode: that is, if they are inputs before Suspend, they are still inputs during
Suspend (the GPIO_CSs can be used to wake up the system); if they are outputs before Suspend, they are still outputs during
Suspend (the GPIO_CSs can be programmed to change state by mode). As inputs, the pullup or pulldown on the signal can be
disabled; if disabled, it is disabled in all modes. When the signal is an output, the built-in resistors are automatically disabled.
When enabled, the Latched Battery Low Detect function (LBL2) that is shared on GPIO19 is an output in all modes; there are
no pullup or pulldown resistors active.
On the ÉlanSC400 microcontroller, the PC Card functions shared on these pins are programmable by PC Card socket; the
pin multiplexing options are explained earlier in this document. For the PC Card power control (PCMA_VCC, PCMA_VPP1,
PCMA_VPP2, PCMB_VCC, PCMB_VPP1, PCMB_VPP2), the signals are outputs for each mode.
For the second Card Detect (CD_A2):
–Reset invokes pullup.
–During normal operation, the pullup resistor can be disabled by a register bit.
–During Suspend mode, the input will have a pulldown if the PC Card Socket A interface is programmed to be powered off
in Suspend mode (Power-Down Group G). If the socket is not programmed to be powered off in Suspend mode, the input
will have the same state as when operating: the pullup is programmable to be enabled or not.
2. The PC Card signals MCEL_B, MCEH_B, RST_B, REG_B, CD_B, RDY_B, BVD1_B, BVD2_B, WP_B, CD_A2,
PCMB_VPP2, PCMB_VPP1, PCMB_VCC, PCMA_VPP1, PCMA_VPP2, and PCMA_VCC are not supported on the
ÉlanSC410 microcontroller.
3. The shared parallel port, PC Card Socket B control, and GPIO signals:
–These signals default to the GPIO interface on reset.
–As a parallel port in Suspend mode, these signals are programmable to accommodate the parallel port powered up or
down.
–As PC Card control on the ÉlanSC400 microcontroller, these signals have the same features as the Socket A control
signals.
–As GPIOs, these signals are not handled specially in Suspend, they remain the same as they were when the chip was
active (i.e., they remain as inputs with the pullup enabled or not, or continue to drive out the same value if they were
outputs).
Summary: Shared parallel port/PC Card Socket B/GPIO signals: Built-in pullup and pulldown resistors that are invoked by:
–Reset invokes pullups
–As parallel port signals:
•Operating: pullups are enabled if not EPP mode. Outputs without pullup or pulldowns if EPP mode.
•Suspend: pullups are enabled, unless the parallel port is programmed to be powered off in Suspend mode, in which
case pulldowns are enabled.
•If EPP mode is enabled for the parallel port, the outputs are driven out at their last value in Suspend mode.
–As PC Card Socket B signals (ÉlanSC400 microcontroller only):
•Operating: outputs have no pullups or pulldowns; inputs have pullups that can be disabled by programming a bit.
•Suspend: outputs are driven out inactive with no pullups or pulldowns unless the PC Card Socket B is programmed
to be powered off in Suspend mode; then the outputs go to three-state with pulldown resistors; inputs will be the
same as they were when operating, with a pullup resistor that can be disabled by programming, unless the PC Card
Socket B is programmed to be powered off in Suspend mode (Power-Down Group H), in which case the inputs have
pulldown resistors enabled.
–As GPIO signals:
•Operating or Suspend: as outputs they have no pullups or pulldowns; as inputs they have pullups that can be dis-
abled by programming a bit; no change of state when the system goes to Suspend.
48
Élan™SC400 and ÉlanSC410 Microcontrollers Data Sheet
AMD [ AMD ]
