Datasheet

DS8007
Multiprotocol Dual Smart Card Interface
12 ______________________________________________________________________________________
Pin Description (continued)
PIN NAME FUNCTION
24 CPB2 Step-Up Converter Contact 4. Connect a low-ESR capacitor of 220nF between CPB1 and CPB2.
25 AGND Analog Ground
26 CPA2 Step-Up Converter Contact 2. Connect a low-ESR capacitor of 220nF between CPA1 and CPA2.
27 V
DD
Digital Supply Voltage. This pin should be decoupled to GND with a good quality capacitor.
28–35 D0–D7
8-Bit Digital I/O. This port functions as the data or address/data communication lines between the host
controller and the DS8007 for the nonmultiplexed and multiplexed operating modes, respectively.
36 RD
Active-Low Parallel Bus Read Strobe Input. In multiplexed mode, this input indicates when the host
processor is reading information from the DS8007. In nonmultiplexed mode, this pin signals the current
operation is a read (RD = 1) or a write (RD = 0) when CS and WR are low.
37 WR
Active-Low Parallel Bus Write Strobe Input. In multiplexed mode, this input indicates when the host
processor is writing information to the DS8007. In nonmultiplexed mode, a low on this pin signals the bus
is engaged in a read or write operation.
38 CS Active-Low Chip-Select Input. This input indicates when the DS8007 is active on the parallel bus.
39 ALE
Address Latch Enable Input. This signal monitors the ALE signal when the host processor bus is
operating in multiplexed mode. Connect this signal to V
DD
when operating in nonmultiplexed mode.
40 INT Active-Low Interrupt. This output indicates an interrupt is active.
41 INTAUX Auxiliary Interrupt Input. This pin serves as an auxiliary interrupt.
42–45 AD3–AD0
Register Selection Address Inputs. These pins function as the address input lines for the nonmultiplexed
configuration and should be connected to ground or V
DD
in the multiplexed configuration.
46, 47
XTAL2,
XTAL1
Crystal Oscillators. Place a crystal with appropriate load capacitors between these pins if that is the
desired clock source. XTAL1 also acts as an input if there is an external clock source in place of a
crystal.
48 DELAY
External Delay Capacitor Connection. Connect a capacitor from this pin to ground to set the power-on
reset delay.