Cypress CY7C024BV Manual De Usuario
CY7C024AV/024BV/025AV/026AV
CY7C0241AV/0251AV/036AV
Document #: 38-06052 Rev. *J
Page 7 of 19
Table 1. Non-Contending Read/Write
Inputs
Outputs
Operation
CE
R/W
OE
UB
LB
SEM
IO
9
–IO
17
IO
0
–IO
8
H
X
X
X
X
H
High Z
High Z
Deselected: Power Down
X
X
X
H
H
H
High Z
High Z
Deselected: Power Down
L
L
X
L
H
H
Data In
High Z
Write to Upper Byte Only
L
L
X
H
L
H
High Z
Data In
Write to Lower Byte Only
L
L
X
L
L
H
Data In
Data In
Write to Both Bytes
L
H
L
L
H
H
Data Out
High Z
Read Upper Byte Only
L
H
L
H
L
H
High Z
Data Out
Read Lower Byte Only
L
H
L
L
L
H
Data Out
Data Out
Read Both Bytes
X
X
H
X
X
X
High Z
High Z
Outputs Disabled
H
H
L
X
X
L
Data Out
Data Out
Read Data in Semaphore Flag
X
H
L
H
H
L
Data Out
Data Out
Read Data in Semaphore Flag
H
X
X
X
L
Data In
Data In
Write D
IN0
into Semaphore Flag
X
X
H
H
L
Data In
Data In
Write D
IN0
into Semaphore Flag
L
X
X
L
X
L
Not Allowed
L
X
X
X
L
L
Not Allowed
Table 2. Interrupt Operation Example (assumes BUSY
L
= BUSY
R
= HIGH)
[10]
Left Port
Right Port
Function
R/W
L
CE
L
OE
L
A
0L–13L
INT
L
R/W
R
CE
R
OE
R
A
0R–13R
INT
R
Set Right INT
R
Flag
L
L
X
FFF
X
X
X
X
X
L
Reset Right INT
R
Flag
X
X
X
X
X
X
L
L
FFF (or 1/3FFF)
H
Set Left INT
L
Flag
X
X
X
X
L
L
L
X
1FFE (or 1/3FFE)
X
Reset Left INT
L
Flag
X
L
L
1FFE
H
X
X
X
X
X
Table 3. Semaphore Operation Example
Function
IO
0
–IO
17
Left
IO
0
–IO
17
Right
Status
No action
1
1
Semaphore-free
Left port writes 0 to semaphore
0
1
Left Port has semaphore token
Right port writes 0 to semaphore
0
1
No change. Right side has no write access to semaphore
Left port writes 1 to semaphore
1
0
Right port obtains semaphore token
Left port writes 0 to semaphore
1
0
No change. Left port has no write access to semaphore
Right port writes 1 to semaphore
0
1
Left port obtains semaphore token
Left port writes 1 to semaphore
1
1
Semaphore-free
Right port writes 0 to semaphore
1
0
Right port has semaphore token
Right port writes 1 to semaphore
1
1
Semaphore free
Left port writes 0 to semaphore
0
1
Left port has semaphore token
Left port writes 1 to semaphore
1
1
Semaphore-free
Notes
10. See
on page 5 for specific highest memory locations by device.
11. If BUSY
R
=L, then no change.
12. If BUSY
L
=L, then no change.
13. See
on page 5 for specific addresses by device.