FlexROM™ III Timing Specifications

Timing Specifications

The following specifications assume:
- All Filtering has been disabled.
- The Latching options have been left at the default setting of (CS and WT active).
- Latch delay has been disabled.

Enabling Filtering and/or Latch delaying adds 10-40ns to the Tcr-2. Tcr-3 and Tcr-4 specs. Enabling Latch on (CS) or Latch on (CS and NOT OE) with MINIMUM delay selected reduces Twp to 20ns. Higher delay settings could result in longer Trdc & Twtc requirements.

Read Cycles:

Symbol Name Description Value
Trdc Read Cycle Time for a complete read cycle 45ns (max)
Tacc Address Access Time from address stable to data valid 45ns (max)
Tcs CS Access
Fast-CS enabled
Fast-CS disabled
Time from CS active to data valid
12ns (max)
45ns (max)
Toe CS Access
Fast-OE enabled
Fast-OE disabled
Time from OE active to data valid
12ns (max)
30ns (max)
Todo OE to data disable Time from rising edge OE to data float 0 - 6ns
Tcod CS to data disable Time from rising edge CS to data float 0 - 12ns
Tcr-1 Cycle Recovery time, valid data Minimum recovery after a read 0ns (min)
NOTE: Data will be valid after ALL access time specs have been meet; Tacc after address stable, Tcs after CS active and Toe after OE active.

Write Cycles (WT controlled/CS controlled):

Symbol Name Description Value
Twtc Write Cycle Time for a complete write cycle 45ns (max)
Tas Address Setup time Address stable to falling edge WT/CS 0ns (min)
Tah Address Hold time Address held after rising edge WT/CS 0ns (min)
Tds Data Setup time Data stable to rising edge WT/CS 10ns (min)
Tdh Data Hold time Data held after rising edge WT/CS 0ns (min)
Twp WT pulse width Minimum WT active pulse width 25ns (min)
Todw WT to data disable Time from falling edge WT to data float (if CS & OE were active) 0 - 12ns
Tcr-2 Cycle recovery time, writes Minimum recovery time after a write 20ns (min)

Snap-shot and Trigger functions

Symbol Name Description Value
Tcr-3 Cycle Recovery time, reads Minimum recovery time after a read 10ns (min)
Tcr-4 Cycle recovery time, writes Minimum recovery time after a write 25ns (min)
Top OE pulse width Minimum OE active pulse 25ns (min)
NOTE: Violation of the Snap-shot/Trigger specs will not cause target side failures unless their specs are being violated as well.