CY7C056V
CY7C057V
Table 1. Non-Contending Read/Write[3]
Inputs
CE R/W OE
H
X
X
B0, B1, B2, B3
X
X
X
X
All H
L
L
X
H/L
L
L
X
All L
L
H
L
H/L
L
H
L
All L
X
X
H
X
H
H
L
X
X
H
L
All H
H
X
X
SEM
H
H
H
H
H
H
X
L
L
L
Outputs
I/O0–I/O35
High Z
High Z
Data In and High Z
Data In
Data Out and High Z
Data Out
High Z
Data Out
Data Out
Data In
Operation
Deselected: Power-Down
Deselected: Power-Down
Write to Selected Bytes Only
Write to All Bytes
Read Selected Bytes Only
Read All Bytes
Outputs Disabled
Read Data in Semaphore Flag
Read Data in Semaphore Flag
Write DIN0 into Semaphore Flag
X
X
All H
L
Data In
Write DIN0 into Semaphore Flag
L
X
X
Any L
L
Table 2. Interrupt Operation Example (assumes BUSYL = BUSYR = HIGH)[3, 44]
Left Port
Not Allowed
Right Port
Function
R/WL CEL OEL
Set Right INTR Flag
L
L
X
Reset Right INTR Flag
X
X
X
Set Left INTL Flag
X
X
X
Reset Left INTL Flag
X
L
L
A0L–13L
3FFF
X
X
3FFE
INTL R/WR CER
X
X
X
X
X
L
L[45]
L
L
H[46]
X
X
OER
X
L
X
X
A0R–13R
X
3FFF
3FFE
X
INTR
L[46]
H[45]
X
X
Table 3. Semaphore Operation Example
Function
No Action
I/O0–I/O8 Left
1
Left Port Writes 0 to Semaphore
0
Right Port Writes 0 to
0
Semaphore
Left Port Writes 1 to Semaphore
1
Left Port Writes 0 to Semaphore
1
Right Port Writes 1 to
0
Semaphore
Left Port Writes 1 to Semaphore
1
Right Port Writes 0 to
1
Semaphore
Right Port Writes 1 to
1
Semaphore
Left Port Writes 0 to Semaphore
0
Left Port Writes 1 to Semaphore
1
Notes:
44. A0L–14L and A0R–14R, 7FFF/7FFE for the CY7C057V.
45. If BUSYR=L, then no change.
46. If BUSYL=L, then no change.
Document #: 38-06055 Rev. **
I/O0–I/O8 Right
1
1
1
0
0
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
1
Semaphore Free
0
Right Port Has Semaphore Token
1
Semaphore Free
1
Left Port Has Semaphore Token
1
Semaphore Free
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