CY7C008/009
CY7C018/019
Document #: 38-06041 Rev. *A Page 16 of 19
Notes:
42. A
0L–16L
and A
0R–16R
, 1FFFF/1FFFE for the CY7C009/019.
43. If BUSY
R
=L, then no change.
44. If BUSY
L
=L, then no change.
Table 1. Non-Contending Read/Write
Inputs Outputs
CE R/W OE SEM I/O
0
–I/O
8
Operation
H X X H High Z Deselected: Power-Down
H H L L Data Out Read Data in Semaphore Flag
X X H X High Z I/O Lines Disabled
H X L Data In Write into Semaphore Flag
L H L H Data Out Read
L L X H Data In Write
L X X L Not Allowed
Table 2. Interrupt Operation Example (assumes BUSY
L
=BUSY
R
=HIGH)
[42]
Left Port Right Port
Function R/W
L
CE
L
OE
L
A
0L–16L
INT
L
R/W
R
CE
R
OE
R
A
0R–16R
INT
R
Set Right INT
R
Flag L L X FFFF (or 1FFFF) X X X X X L
[44]
Reset Right INT
R
Flag X X X X X X L L FFFF (or 1FFFF) H
[43]
Set Left INT
L
Flag X X X X L
[43]
L L X FFFE (or 1FFFE) X
Reset Left INT
L
Flag X L L FFFE (or 1FFFE) H
[44]
X X X X X
Table 3. Semaphore Operation Example
Function I/O
0
–I/O
8
Left I/O
0
–I/O
8
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
