2−20

Table 2−11. 16-Bit PC Card Interface Control TerminalsExternal components are not applicable for the 16-bit PC Card interface control terminals. If any 16-bit PC Cardinterface control terminal is unused, then the terminal may be left floating.
SKT A TERMINAL SKT B TERMINAL†
DESCRIPTION
I/O
POWER
NAME NO. NAME NO. DESCRIPTION
I/O
TYPE
POWER
RAIL
A_BVD1
(STSCHG/RI) B02 B_BVD1
(STSCHG/RI) F14
Battery voltage detect 1. BVD1 is generated by 16-bit memory PC Cards that
include batteries. BVD1 is used with BVD2 as an indication of the condition of the
batteries on a memory PC Card. Both BVD1 and BVD2 are high when the battery
is good. When BVD2 is low and BVD1 is high, the battery is weak and must be
replaced. When BVD1 is low, the battery is no longer serviceable and the data in
the memory PC Card is lost. See Section 5.6, ExCA Card Status-Change Interrupt
Configuration Register, for enable bits. See Section 5.5, ExCA Card
Status-Change Register, and Section 5.2, ExCA Interface Status Register, for the
status bits for this signal.
Status change. STSCHG alerts the system to a change in the READY, write
protect, or battery voltage dead condition of a 16-bit I/O PC Card.
Ring indicate. RI is used by 16-bit modem cards to indicate a ring detection.
IVCCA/
VCCB
A_BVD2
(SPKR)A02 B_BVD2
(SPKR)C17
Battery voltage detect 2. BVD2 is generated by 16-bit memory PC Cards that
include batteries. BVD2 is used with BVD1 as an indication of the condition of the
batteries on a memory PC Card. Both BVD1 and BVD2 are high when the battery
is good. When BVD2 is low and BVD1 is high, the battery is weak and must be
replaced. When BVD1 is low, the battery is no longer serviceable and the data in
the memory PC Card is lost. See Section 5.6, ExCA Card Status-Change Interrupt
Configuration Register, for enable bits. See Section 5.5, ExCA Card
Status-Change Register, and Section 5.2, ExCA Interface Status Register, for the
status bits for this signal.
Speaker. SPKR is an optional binary audio signal available only when the card and
socket have been configured for the 16-bit I/O interface. The audio signals from
cards A and B are combined by the controller and are output on SPKROUT.
DMA request. BVD2 can be used as the DMA request signal during DMA
operations to a 16-bit PC Card that supports DMA. The PC Card asserts BVD2 to
indicate a request for a DMA operation.
IVCCA/
VCCB
A_CD1
A_CD2
C15
E05 B_CD1
B_CD2
N13
B17
Card detect 1 and card detect 2. CD1 and CD2 are internally connected to ground
on the PC Card. When a PC Card is inserted into a socket, CD1 and CD2 are
pulled low. For signal status, see Section 5.2, ExCA Interface Status Register.I
A_CE1
A_CE2
G12
B12 B_CE1
B_CE2
M18
L19
Card enable 1 and card enable 2. CE1 and CE2 enable even- and odd-numbered
address bytes. CE1 enables even-numbered address bytes, and CE2 enables
odd-numbered address bytes. OVCCA/
VCCB
A_INPACK E07 B_INPACK E18
Input acknowledge. INPACK is asserted by the PC Card when it can respond to an
I/O read cycle at the current address.
DMA request. INPACK can be used as the DMA request signal during DMA
operations from a 16-bit PC Card that supports DMA. If it is used as a strobe, then
the PC Card asserts this signal to indicate a request for a DMA operation.
IVCCA/
VCCB
A_IORD C11 B_IORD L15
I/O read. IORD is asserted by the controller to enable 16-bit I/O PC Card data
output during host I/O read cycles.
DMA write. IORD is used as the DMA write strobe during DMA operations from a
16-bit PC Card that supports DMA. The controller asserts IORD during DMA
transfers from the PC Card to host memory.
OVCCA/
VCCB
A_IOWR E11 B_IOWR L13
I/O write. IOWR is driven low by the controller to strobe write data into 16-bit I/O
PC Cards during host I/O write cycles.
DMA read. IOWR is used as the DMA write strobe during DMA operations from a
16-bit PC Card that supports DMA. The controller asserts IOWR during transfers
from host memory to the PC Card.
OVCCA/
VCCB
†These terminals are reserved for the PCI7611 and PCI7411 controllers.