S1M1V045 Epson Electronics America, Inc., S1M1V045 Datasheet - Page 8

• Manufacturer Part Number: S1M1V045
• Description: Full CMOS Asynchronous SRAM
• Manufacturer: Epson Electronics America, Inc.

S1M1V045B0J7
8
(1) Reading data from byte
Since I/O pins are in "Hi-Z" state when O
access time is apparently able to be cut down.
Writing data
(1)Writing data into lower byte
Anyway, data on I/O pins are latched up into the memory cell during CS1 = "Low", CS2 ="High", WE and LB =
"Low".
(2)Writing data into upper byte
Anyway, data on I/O pins are latched up into the memory cell during C
"Low".
(3)Writing data into both bytes
Anyway, data on I/O pins are latched up into the memory cell during C
UB and LB = "Low".
(1)Writing data into byte
Anyway, data on I/O pins are latched up into the memory cell during C
"Low".
As DATA I/O pins are in "Hi-Z" when C
mode), the contention on the data bus can be avoided. But while I/O pins are in the output state, the data that is
opposite to the output data should not be given.
Byte-mode
Word-mode
Byte-mode
Data is able to read when address and SA are set while holding C
and W
There are the following four ways of writing data into the memory.
i) Hold CS2 = "High", WE = "Low", UB = "High", and LB = "Low", set address and give "Low" pulse to CS1.
ii) Hold CS1 = "Low", WE = "Low", UB = "High", and LB = "Low", set address and give "High" pulse to CS2.
iii) Hold CS1 = "Low", CS2 = "High", UB = "High", and LB = "Low", set address and give "Low" pulse to WE.
iv)Hold CS1 = "Low", CS2 = "High", WE = "Low", and UB = "High", set address and give "Low" pulse to LB.
There are the following four ways of writing data into the memory.
i) Hold CS2 = "High", W
ii) Hold CS1 = "Low", W
iii) Hold CS1 = "Low", CS2 = "High", LB = "High", and UB = "Low", set address and give "Low" pulse to WE.
iv)Hold CS1 = "Low", CS2 = "High", WE = "Low", and LB = "High", set address and give "Low" pulse to UB.
There are the following four ways of writing data into the memory.
i) Hold CS2 = "High", W
ii) Hold CS1 = "Low", W
iii) Hold CS1 = "Low", CS2 = "High", LB and UB = "Low", set address and give "Low" pulse to WE.
iv)Hold CS1 = "Low", CS2 = "High", WE = "Low", set address and give "Low" pulse to LB and UB.
There are the following three ways of writing data into the memory.
i)
ii) Hold C
iii) Hold C
Hold CS2 = "High", W
–
–
E
= "High".
–
–
–
–
S
S
–
–
1
1
= "Low", CS2 = "High", set address and SA, then give "Low" pulse to W
= "Low", W
–
–
–
–
–
–
–
–
–
E
–
E
E
E
–
–
E
E
= "Low", LB = "High", and UB = "Low", set address and give "High" pulse to CS2.
= "Low", LB and UB = "Low", set address and give "High" pulse to CS2.
= "Low", LB = "High", and UB = "Low", set address and give "Low" pulse to C
= "Low", LB and UB = "Low", set address and give "Low" pulse to C
= "Low", set address and SA, then give "High" pulse to CS2.
= "Low", set address and SA, then give "Low" pulse to C
–
–
–
S
–
E
–
1
= "High", CS2 = "Low", O
= "High", the data bus line can be used for any other objective, then
–
–
–
–
E
–
–
S
–
–
S
= "High", or LB and UB = "High" (Word-
–
–
1
–
–
1
S
S
–
–
1
= "Low", CS2 ="High", WE = "Low",
1
= "Low", CS2 ="High", WE and UB =
= "Low" , CS2 ="High" , and W
= "Low", CS2= "High", O
–
–
–
S
–
–
E
1
.
.
–
–
S
–
–
–
1
E
.
="Low",
Rev.1.0
–
–
–
–
E
S
–
1
=
.