IDT7027S/L
High-Speed 32K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Truth Table I Chip Enable
CE1
Mode
CE
CE0
V
IL
V
IH
Port Selected (TTL Active)
L
< 0.2V
>VCC -0.2V
X
Port Se le cte d (CMOS Active )
Port Deselected (TTL Inactive)
Port Deselected (TTL Inactive)
Po rt Deselected (CMOS Inactive)
Port Deselected (CMOS Inactive)
V
IH
X
V
IL
H
>VCC -0.2V
X
X
<0.2V
3199 tbl 02
NOTES:
1. Chip Enable references are shown above with the actual CE0 and CE1 levels, CE is a reference only.
2. Port "A" and "B" references are located where CE is used.
3. "H" = VIH and "L" = VIL.
Truth Table II Non-Contention Read/Write Control
Inputs(1)
Outputs
CE(2)
H
X
L
OE
X
X
X
X
X
L
UB
X
H
L
LB
X
H
H
L
SEM
H
R/W
X
X
L
I/O8-15
I/O0-7
High-Z
High-Z
High-Z
DATAIN
DATAIN
High-Z
Mode
Deselected: Power-Down
Both Bytes Deselected
Write to Upper Byte Only
Write to Lower Byte Only
Write to Both Bytes
High-Z
High-Z
H
H
DATAIN
High-Z
L
L
H
L
H
L
L
L
H
DATAIN
DATAOUT
High-Z
L
H
H
H
X
L
H
L
H
Read Upper Byte Only
L
L
H
L
H
DATAOUT Read Lower Byte Only
DATAOUT Read Both Bytes
L
L
L
H
DATAOUT
High-Z
X
H
X
X
X
High-Z
Outputs Disabled
3199 tbl 03
NOTES:
1. A0L — A14L ≠ A0R — A14R.
2. Refer to Chip Enable Truth Table.
Truth Table III Semaphore Read/Write Control
Inputs(1)
Outputs
(2)
R/
W
I/O8-15
DATAOUT
DATAOUT
DATAIN
I/O0-7
Mode
CE
OE
L
UB
X
H
X
H
L
LB
X
H
X
H
X
L
SEM
L
H
H
DATAOUT Read Data in Semaphore Flag
DATAOUT Read Data in Semaphore Flag
X
H
↑
L
L
H
X
X
X
X
L
DATAIN
Write I/O0 into Semaphore Flag
Write I/O0 into Semaphore Flag
Not Allowed
X
L
L
DATAIN
DATAIN
↑
______
______
X
X
L
______
______
L
X
L
Not Allowed
3199 tbl 04
NOTES:
1. There are eight semaphore flags written to via I/O0 and read from all the I/Os (I/O0 __I/O15). These eight semaphore flags are addressed by A0-A2.
2. Refer to Chip Enable Truth Table.
4
6.42
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
