CY7C008 CYPRESS [Cypress Semiconductor], CY7C008 Datasheet - Page 16

• Manufacturer Part Number: CY7C008
• Description: 64K/128K x 8/9 Dual-Port Static RAM
• Manufacturer: CYPRESS [Cypress Semiconductor]

Table 1. Interrupt Operation Example (assumes BUSY
Table 2. Semaphore Operation Example
Notes:
Document #: 38-06041 Rev. *C
43. A
44. If BUSY
45. If BUSY
Set Right INT
Reset Right INT
Set Left INT
Reset Left INT
No action
Left port writes 0 to semaphore
Right port writes 0 to semaphore
Left port writes 1 to semaphore
Left port writes 0 to semaphore
Right port writes 1 to semaphore
Left port writes 1 to semaphore
Right port writes 0 to semaphore
Right port writes 1 to semaphore
Left port writes 0 to semaphore
Left port writes 1 to semaphore
CE
H
H
X
H
L
L
L
0L–16L
Function
and A
R
L
R/W
=L, then no change.
=L, then no change.
H
H
X
X
X
Function
L
L
R
Flag
0R–16R
Inputs
L
Flag
Flag
R
Flag
, 1FFFF/1FFFE for the CY7C009/019.
OE
H
X
X
X
X
L
L
R/W
X
X
X
L
SEM
L
H
X
H
H
L
L
L
CE
X
X
L
L
I/O
High Z
Data Out
High Z
Data In
Data Out
Data In
L
0
–I/O
Outputs
I/O
1
0
0
1
1
0
1
1
1
0
1
OE
X
X
X
L
8
0
–I/O
Left
Left Port
L
8
FFFF (or 1FFFF)
FFFE (or 1FFFE)
I/O
A
0
0L–16L
Deselected: Power-Down
Read Data in Semaphore Flag
I/O Lines Disabled
Write into Semaphore Flag
Read
Write
Not Allowed
–I/O
X
X
L
1
1
1
0
0
1
1
0
1
1
1
=BUSY
8
Right
R
=HIGH)
Semaphore free
Left port has semaphore token
No change. Right side has no write access to semaphore
Right port obtains semaphore token
No change. Left port has no write access to semaphore
Left port obtains semaphore token
Semaphore free
Right port has semaphore token
Semaphore free
Left port has semaphore token
Semaphore free
INT
H
L
X
X
[44]
[45]
L
[43]
R/W
X
X
L
X
R
Operation
CE
X
X
L
L
R
OE
Status
X
X
X
L
Right Port
R
FFFF (or 1FFFF)
FFFE (or 1FFFE)
CY7C008/009
CY7C018/019
A
0R–16R
X
X
Page 16 of 19
INT
H
L
X
X
[45]
[44]
R