
IDT70P257/247L
Low Power 1.8V 8K/4K x 16 Dual-Port Static RAM
Truth Table II: Semaphore Read/Write Control (1)
Industrial Temperature Range
Inputs
Outputs
CE
H
X
H
X
L
L
R/ W
H
H
↑
↑
X
X
OE
L
L
X
X
X
X
UB
X
H
X
H
L
X
LB
X
H
X
H
X
L
SEM
L
L
L
L
L
L
I/O 8-15
DATA OUT
DATA OUT
DATA IN
DATA IN
____
____
I/O 0-7
DATA OUT
DATA OUT
DATA IN
DATA IN
____
____
Mode
Read Data in Semaphore Flag
Read Data in Semaphore Flag
Write D IN0 into Semaphore Flag
Write D IN0 into Semaphore Flag
Not Allowed
Not Allowed
5684 tbl 03
NOTE:
1. There are eight semaphore flags written to via I/O 0 and read from all of the I/O's (I/O 0 -I/O 15 ). These eight semaphores are addressed by A 0 -A 2 .
Absolute Maximum Ratings (1)
Symbol
V TERM
Rating
Supply Voltage on V DD
Industrial
-0.5 to +2.9
Unit
V
with Respect to GND
V TERM (2)
Terminal Voltage with
-0.5 to V DD +0.3
V
Respect to GND
T BIAS (3)
T STG
T JN
Temperature Under Bias
Storage Temperature
Junction Temperature
-55 to +125
-65 to +150
+150
o
o
o
C
C
C
I OUT
DC Output Current
20
mA
5684 tbl 04
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent
damage to the device. This is a stress rating only and functional operation of the device at these
or any other conditions above those indicated in the operational sections of this specification is
not implied. Exposure to absolute maximum rating conditions for extended periods may affect
reliability.
2. V TERM must not exceed V DD + 0.3V for more than 25% of the cycle time or 10ns maximum, and
is limited to < 20mA for the period over V TERM = V DD + 0.3V .
3. Ambient Temperature under DC Bias. No AC Conditions. Chip Deselected.
6.42