CY7C006A_13 Datasheet, PDF (16/22 Pages) Cypress Semiconductor – 16 K × 8 Dual-Port Static RAM

CY7C006A
Non-Contending Read/Write
Inputs
Outputs
CE R/W OE SEM
I/O₀–I/O₈
H
X
X
H High Z
H
H
L
L Data Out
X
X
H
X High Z
H
X
L Data In
L
H
L
H Data Out
L
L
X
H Data In
L
X
X
L
Deselected: Power-Down
Read Data in Semaphore Flag
I/O Lines Disabled
Write into Semaphore Flag
Read
Write
Not Allowed
Operation
Interrupt Operation Example
(Assumes BUSY_L = BUSY_R = HIGH)
Function
R/W_L CE_L
Set Right INT_R Flag
L
L
Reset Right INT_R Flag
X
X
Set Left INT_L Flag
X
X
Reset Left INT_L Flag
X
L
Left Port
OE_L
X
A_0L–14L
3FFF
X
X
X
X
L
3FFE
INT_L
X
X
L^[38]
H^[37]
R/W_R
X
X
L
X
CE_R
X
L
L
X
Right Port
OE_R
X
A_0R–14R
X
L
3FFF
X
3FFE
X
X
INT_R
L^[37]
H^[38]
X
X
Semaphore Operation Example
Function
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
I/O₀–I/O₈ Left
1
0
0
1
1
0
1
1
1
0
1
I/O₀–I/O₈Right
1
1
1
0
0
1
1
0
1
1
1
Status
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
Notes
37. If BUSY_L = L, then no change.
38. If BUSY_R = L, then no change.
Document Number: 38-06045 Rev. *G
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