UPSD3254 STMICROELECTRONICS [STMicroelectronics], UPSD3254 Datasheet - Page 146

• Manufacturer Part Number: UPSD3254
• Description: Flash Programmable System Devices with 8032 Microcontroller Core
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

UPSD3254A, UPSD3254BV, UPSD3253B, UPSD3253BV
Table 110. AC Symbols for Timing
Example: t
Invalid.
Figure 74. Switching Waveforms – Key
146/175
W
Q
M
A
C
D
N
P
R
B
L
I
Address
Clock
Input Data
Instruction
ALE
RESET Input or Output
PSEN signal
Output Data
RD signal
WR signal
V
Output Macrocell
STBY
AVLX
Output
–
Time from Address Valid to ALE
Signal Letters
WAVEFORMS
STEADY INPUT
MAY CHANGE FROM
HI TO LO
MAY CHANGE FROM
LO TO HI
DON'T CARE
OUTPUTS ONLY
INPUTS
PW
H
V
X
L
Z
t
Time
Logic Level Low or ALE
Logic Level High
Valid
No Longer a Valid Logic Level
Float
Pulse Width
STEADY OUTPUT
WILL BE CHANGING
FROM HI TO LO
WILL BE CHANGING
LO TO HI
CHANGING, STATE
UNKNOWN
CENTER LINE IS
TRI-STATE
OUTPUTS
Signal Behavior
AI03102