Datasheet
2–6
Table 2–6. Miscellaneous Terminals
TERMINAL
I/O
DESCRIPTION
NAME NO.
I/O
DESCRIPTION
CYCLEIN 87 I/O
The CYCLEIN terminal allows an external 8-kHz clock to be used as a cycle timer for synchronization with other
system devices.
If this terminal is not implemented, it must be pulled high to DV
DD
through a pullup resistor.
CYCLEOUT/
CARDBUS
86 I/O
This terminal is sampled when G_RST is asserted and is used to select between PC Card and non-PC Card
implementations. If CARDBUS
is sampled low at reset, software programs an appropriate value into the
CardBus CIS base address register at offset 18h in the PCI configuration space (see Section 3.11, CardBus
CIS Base Address Register). After reset, this terminal may function as CYCLEOUT. The CYCLEOUT terminal
provides an 8-kHz cycle timer synchronization signal. If CYCLEOUT is not implemented, this terminal must be
pulled up to V
DD
through a pullup resistor. For CardBus implementations, this terminal must be tied to ground
through a pulldown resistor and the pullup resistor is not needed.
GPIO2 90 I/O
General-purpose I/O [2]. This terminal defaults as an input and if it is not implemented, it is recommended that
it be pulled low to ground with a 220-Ω resistor.
GPIO3 89 I/O
General-purpose I/O [3]. This terminal defaults as an input and if it is not implemented, it is recommended that
it be pulled low to ground with a 220-Ω resistor.
REG_EN 9 I Regulator enable. This terminal must be tied to ground to enable the internal voltage regulator. When using a
single 3.3-V supply, this terminal must be tied to ground to enable the internal voltage regulator. When using
a dual 1.8-V/3.3-V supply to provide power to the device, REG_EN
must be pulled to V
DD
to disable the internal
voltage regulator.
SCL 91 I/O
Serial clock. This terminal provides the serial clock signaling and is implemented as open-drain. For normal
operation (a ROM is implemented in the design), this terminal must be pulled high to the ROM V
DD
with a 2.7-kΩ
resistor. Otherwise, it must be pulled low to ground with a 220-Ω resistor.
SDA 92 I/O
Serial data. At PCI_RST, the SDA signal is sampled to determine if a two-wire serial ROM is present. If the serial
ROM is detected, this terminal provides the serial data signaling.
This terminal is implemented as open-drain, and for normal operation (a ROM is implemented in the design),
this terminal must be pulled high to the ROM V
DD
with a 2.7-kΩ resistor. Otherwise, it must be pulled low to
ground with a 220-Ω resistor.
TEST17
TEST16
TEST9
TEST8
TEST3
TEST2
TEST1
TEST0
10
11
94
95
101
102
104
105
I/O
Terminals TEST[9, 8, 3, 2, 1, 0] are used for factory test of the TSB43AB22A device and must be connected
to ground for normal operation.
Terminal TEST[17:16] must be pulled to V
DD
. These terminals can be pulled to V
DD
through a common pullup
resistor.