Datasheet

DS8007
Multiprotocol Dual Smart Card Interface
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AC ELECTRICAL SPECIFICATIONS—TIMING PARAMETERS FOR CONSECUTIVE
READ/WRITE TO URR/UTR/TOC
(V
DD
= 3.3V, V
DDA
= 3.3V, T
A
= +25°C, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SEE FIGURE 3
RD Pulse Width t
W(RD)
10 ns
RD Low to Bit CRED = 1 t
RD(URR)
t
W(RD)
+
2t
CY(CLK)
t
W(RD)
+
3t
CY(CLK)
ns
Set Time Bit FE t
SB(FE)
10.5 ETU
Set Time Bit RBF t
SB(RBF)
10.5 ETU
SEE FIGURE 4
WR/CS Pulse Width t
W(WR)
(Note 4) 10 ns
WR/CS Low to I/Ox Low t
WR(UTR)
t
W(WR)
+
2t
CY(CLK)
t
W(WR)
+
3t
CY(CLK)
ns
SEE FIGURE 5
WR/CS Pulse Width t
W(WR)
10 ns
WR/CS High to Bit CRED = 1 t
WR(TOC)
(Notes 4 and 5) 1 / PSC 2 / PSC ETU
t
SB(RBF)
t
W(RD)
t
SB(FE)
I/Ox
RBF BIT
FE BIT
INT
RD
CRED BIT
t
RD(URR)
Figure 3. Timing Between Two Read Operations in Register URR
Note 4: Depends on the leading edge of WR or CS (whichever is deasserted first). Reference this specification to the rising edge
of CS/WR instead of the falling edge.
Note 5: PSC is the programmed prescaler value (31 or 32).