
RF5C296/RF5C396L/RB5C396/RF5C396
50
Power supply to which pins are pulled up
(VCC common to card power supply)
VCC_AT
Pins which must be pulled up
RDY/BSY#,INPACK#,WAIT#,
WP,BVD1,BVD2
CD1#,CD2#,VS1#
The Personal Computer Memory Card Industry Association (PCMCIA) standard requires that some types of
pins should be pulled up on the PC card slots. Besides these pins,there are some pins which must be pulled up on
the system side. They are listed in the table below.
For the RF5C296 and the RF5C396, the VSI# pin, which is connected to the 5VDET/GPI pin internally pulled up,
requires no external pull-up resistor while the other pins listed above require an external pull-up resistor. For
details, see “3.2 5VDET/GPI and VSI# Pins”.
Basically, the CD1# and CD2# pins should be pulled by a power supply which survives after removal of the PC
card from the PC card slot and therefore be confined to the VCC_CORE or the VCC_AT.
For the RF5C296 and the RF5C396, in particular, the CD1# and CD2# pins are powered by, and should therefore
be pulled up to, the VCC_AT.
Originally, the 5VDET/GPI pin is used as a general-purpose input (GPI) pin capable of generating interrupts
upon occurrence of any input change. The VS1# pin is connected to the GND pin on the 3.3V PC card and no con-
nection pin on any other card. The 5VDET/GPI pin, which is internally pulled up as described before, can be con-
nected to the VS1# pin as shown in the figure below to identify whether the PC card supply voltage is 5 or 3.3V.
The 5VDET/GPI pin must be connected to the VS1# pin in consideration of the following :
· An inverted signal from the 5VDET/GPI pin is read back to bit7 in the Interface Status Register.
· Bit2 (GPI Enable Bit) must always be set to “0” in the Card Detect and Control Register.
For details on bit7 in the Interface Status Register and bit2 (GPI Enable Bit) in the Card Detect and Control
Register, see “6. Access to Internal Registers” in “FUNCTIONAL DESCRIPTION”.
VCC3EN#
VCC5EN#
VCCSLOT#
5VDET/GPI
RF5C296/RF5C396
Power Control
Circuits
PCMCIA
Card Slot
VCC
VS1#
3. Connections to PCMCIA Slot
3.2 5VDET/GPI and VS1# Pins
3.1 Pull-up Resistor