ProASICPLUS Flash Family FPGAs
v5.9
2-67
Asynchronous FIFO Read
Note: The plot shows the normal operation status.
Figure 2-40 Asynchronous FIFO Read
Table 2-63 TJ = 0°C to 110°C; VDD = 2.3 V to 2.7 V for Commercial/Industrial
TJ = –55°C to 150°C, VDD = 2.3 V to 2.7 V for Military/MIL-STD-883
Symbol txxx
Description
Min.
Max.
Units
Notes
ERDH, FRDH,
THRDH
Old EMPTY, FULL, EQTH, & GETH valid hold
time from RB
↑
0.5
ns
Empty/full/thresh are invalid from the end
of hold until the new access is complete
ERDA
New EMPTY access from RB
↑
3.01
ns
FRDA
FULL
↓ access from RB ↑
3.01
ns
ORDA
New DO access from RB
↓
7.5
ns
ORDH
Old DO valid from RB
↓
3.0
ns
RDCYC
Read cycle time
7.5
ns
RDWRS
WB
↑, clearing EMPTY, setup to
RB
↓
3.02
ns
Enabling the read operation
1.0
ns
Inhibiting the read operation
RDH
RB high phase
3.0
ns
Inactive
RDL
RB low phase
3.0
ns
Active
RPRDA
New RPE access from RB
↓
9.5
ns
RPRDH
Old RPE valid from RB
↓
4.0
ns
THRDA
EQTH or GETH access from RB
↑
4.5
ns
Notes:
1. At fast cycles, ERDA and FRDA = MAX (7.5 ns – RDL), 3.0 ns.
2. At fast cycles, RDWRS (for enabling read) = MAX (7.5 ns – WRL), 3.0 ns.
RB = (RDB+RBLKB)
RPE
RDATA
EMPTY
EQTH, GETH
FULL
(Empty inhibits read)
Cycle Start
WB
tRDWRS
tERDH, tFRDH
tERDA, tFRDA
tTHRDH
tORDH
tRPRDH
tORDA
tRPRDA
tRDL
tRDH
tRPRDA
tRDL
tRDCYC
tRDH
tTHRDA