Specifications

Élan™SC310 Microcontroller Data Sheet 87
PRELIMINARY
AC SWITCHING CHARACTERISTICS AND WAVEFORMS
The AC specifications provided in the AC characteris-
tics tables that follow consist of output delays, input
setup requirements, and input hold requirements. Fig-
ure 31 provides a key to the switching waveforms.
AC specifications measurement is defined by the fig-
ures that follow each timing table.
Output delays are specified with minimum and maxi-
mum limits, measured as shown. The minimum delay
times are hold times provided to external circuitry.
Input setup and hold times are specified as minimums,
defining the smallest acceptable sampling window.
Within the sampling window, a synchronous input sig-
nal must be stable for correct microcontroller operation.
Figure 31. Key to Switching Waveforms
AC Switching Test Waveforms
Notes:
For AC testing, inputs are driven at 3 V for a logic 1 and 0 V for a logic 0.
WAVEFORMS INPUTS OUTPUTS
Must be Steady Will be Steady
May Change from H to L Will be Changing from H to L
May Change from L to H Will be Changing from L to H
Don’t Care, Any Change Permitted Changing, State Unknown
Does Not Apply Center Line is High-Impedance “Off” State
VCC ÷ 2
VCC ÷ 2
V
IH
= VCC
Input
V
IL
= 0
Test Points
Output