XR82C684CJ-F Datasheet, PDF (14/107 Pages) Exar Corporation – CMOS Quad Channel UART(QUART)

XR82C684
AC ELECTRICAL CHARACTERISTICS ^{1, 2, 3} (CONT’D)
Symbol
Parameter
Receiver Timing XR82C684 (Figure 66)
_8
8! !  (  8

5"  ;(,
_8;
8! ! ;  ( *  8

5"  ;(,
Min.
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Typ. Max.
Unit Conditions
%
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Notes
1 _{Parameters are valid over the specified temperature and operating supply ranges. Typical values are 25
C, VCC = 5V and typical}
processing parameters.
2 _{All voltages are referenced to ground (GND). For testing, input signal levels are 0.4V and 2.4V with a transition time of 20 ns maxi-}
mum. All time measurements are referenced at input voltages of 0.8V and 2.0V as appropriate. See Figure 50.
3 _{AC test conditions for outputs: CL = 50 pF, RL = 2.7 kohm to VCC.}
4 _{If -CS is used as the strobing input, this parameter defines the minimum high time between -CSs.}
5 _{Consecutive write operations to the same register require at least three edges of the X1 clock between writes.}
6 _{This specification imposes a 6 MHz maximum 68000 clock frequency if a read or write cycle follows immediately after the previous}
read or write cycle. A higher 68000 clock can be used if this is not the case.
7 _{This specification imposes a lower bound on -CS and -IACK low, guaranteeing that they will be low for at least one CLK period.}
8 _{This parameter is specified only to insure that -DTACK is asserted with respect to the rising edge of X1/CLK as shown in the timing}
diagram, not to guarantee operation of the part. If the specified setup time is violated, -DTACK may be asserted as shown or may be
asserted one clock cycle later.
9 _{The minimum high time must be at least 1.5 times the X1/CLK period and the minimum low time must be at least equal to the X1/CLK}
period if either channel’s Receiver is operating in external 1X clock mode.
ABSOLUTE MAXIMUM RATINGS¹
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 9


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Notes
1 _{Stresses above those listed under the Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rat-}
ing only, and functional operation of the device at these or any other conditions above those indicated in the “Electrical Characteris-
tics” section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
 
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