AM186EM Datasheet, PDF (60/98 Pages) List of Unclassifed Manufacturers – MICROCONTROLLER BLOCK DIAGRAM

PRELIMINARY
COMMERCIAL SWITCHING CHARACTERISTICS AND WAVEFORMS
In the switching waveforms that follow, several abbre-
viations are used to indicate the specific periods of a
bus cycle. These periods are referred to as time states.
A typical bus cycle is composed of four consecutive
time states: t₁, t₂, t₃, and t₄. Wait states, which represent
multiple t₃ states, are referred to as t_w states. When no bus
cycle is pending, an idle (t_i) state occurs.
In the switching parameter descriptions, the multi-
plexed address is referred to as the AD address bus; the
demultiplexed address is referred to as the A address
bus.
Key to Switching Waveforms
WAVEFORM
INPUT
Must be
Steady
May
Change
from H to L
May
Change
from L to H
Don’t Care,
Any Change
Permitted
Does Not
Apply
Invalid
OUTPUT
Will be
Steady
Will be
Changing
from H to L
Will be
Changing
from L to H
Changing,
State
Unknown
Center
Line is High-
Impedance
Off State
Invalid
60
Am186/188EM and Am186/188EMLV Microcontrollers