CY7C006A_12 Datasheet, PDF (17/22 Pages) Cypress Semiconductor – 32 K/16 K × 8, 16 K × 9 Dual-Port Static RAM

CY7C006A/CY7C007A
CY7C016A/CY7C017A
Table 1. 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
Operation
Deselected: Power-Down
Read Data in Semaphore Flag
I/O Lines Disabled
Write into Semaphore Flag
Read
Write
Not Allowed
Table 2. Interrupt Operation Example (assumes BUSY_L=BUSY_R=HIGH)
Left Port
Function
R/W_L CE_L OE_L
Set Right INT_R Flag
L
L
X
Reset Right INT_R Flag X
X
X
Set Left INT_L Flag
X
X
X
Reset Left INT_L Flag
X
L
L
A_0L–14L
7FFF
X
X
7FFE
INT_L
X
X
L^[47]
H^[48]
R/W_R
X
X
L
X
CE_R
X
L
L
X
Right Port
OE_R
X
A_0R–14R
X
L
7FFF
X
7FFE
X
X
INT_R
L^[48]
H^[47]
X
X
Table 3. 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
Semaphore free
Status
1
Left Port has semaphore token
1
No change. Right side has no write access to semaphore
0
Right port obtains semaphore token
0
No change. Left port has no write access to semaphore
1
Left port obtains semaphore token
1
Semaphore free
0
Right port has semaphore token
1
Semaphore free
1
Left port has semaphore token
1
Semaphore free
Notes
47. If BUSY_R = L, then no change.
48. If BUSY_L= L, then no change.
Document Number: 38-06045 Rev. *F
Page 17 of 22
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