CYDM256A16, CYDM128A16,
CYDM064A16, CYDM128A08,
CYDM064A08
Document #: 38-06081 Rev. *F
Page 8 of 25
Table 4. Output Drive Register [25]
SFEN
CE
R/W
OE
UB
LB
ADDR
I/O0–I/O4 I/O5–I/O15
Mode
HLH
X [26]
L[23]
L[23]
x0000-Max VALID[23] VALID[23] Standard Memory Access
LL
L
X
X
L
x0001
VALID[24]
X
ODR Write[25, 27]
LL
H
L
X
L
x0001
VALID[24]
X
ODR Read[25]
Table 5. Semaphore Operation Example
Function
I/O0–I/O15 Left I/O0–I/O15 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:
23. UB or LB = VIL. If LB = VIL, then DQ<7:0> are valid. If UB = VIL then DQ<15:8> are valid.
24. LB must be active (LB = VIL) for these bits to be valid.
25. SFEN = VIL for ODR reads and writes.
26. Output enable must be low (OE = VIL) during reads for valid data to be output.
27. During ODR writes data will also be written to the memory