UPSD3212C Datasheet, PDF (123/152 Pages) STMicroelectronics – Flash Programmable System Devices with 8032 Microcontroller Core and 16Kbit SRAM

UPSD3212C, UPSD3212CV
Table 88. AC Symbols for Timing
Signal Letters
A Address
C Clock
D Input Data
I Instruction
L ALE
N RESET Input or Output
P PSEN signal
Q Output Data
R RD signal
W WR signal
B VSTBY Output
M Output Macrocell
Example: t_AVLX – Time from Address Valid to ALE
Invalid.
Signal Behavior
t Time
L Logic Level Low or ALE
H Logic Level High
V Valid
X No Longer a Valid Logic Level
Z Float
PW Pulse Width
Figure 64. Switching Waveforms – Key
WAVEFORMS
INPUTS
OUTPUTS
STEADY INPUT
STEADY OUTPUT
MAY CHANGE FROM
HI TO LO
MAY CHANGE FROM
LO TO HI
WILL BE CHANGING
FROM HI TO LO
WILL BE CHANGING
LO TO HI
DON'T CARE
OUTPUTS ONLY
CHANGING, STATE
UNKNOWN
CENTER LINE IS
TRI-STATE
AI03102
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